Undergraduate Thesis - David Rate - Comparison of Impact and Transfer Stains in Bloodstainpattern...

Attempting to Differentiate Impact Spatter Stains from

Transfer Stains on Apparel Fabrics

Presented to the Department of Forensic Science, Trent University in partial fulfillment of

the requirements for the degree of the Bachelor of Science in Forensic Science

By: David Rate

Peterborough Ontario, February 2nd, 2015

Internal Supervisor and Coordinator: Dr. Barry Saville

External Supervisor: Dr. Brian Yamashita

Secondary Reader: Gordon Lefebrve

© 2015, David Rate

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I submit this thesis in partial fulfillment of the requirements for the degree of the Bachelor

of Science in Forensic Science at Trent University.

_____________________________________ _______________________

(Student’s Signature) (Date Submitted)

This document fulfills the criteria for a thesis set out by the Department of Forensic

Science in Trent University, Peterborough, ON.

_____________________________________ _______________________

(Supervisor’s Signature) (Date)

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Abstract

The examination of bloodstains on clothing can provide useful information

regarding the actions and movement of the wearer. For this reason, it is a common request

for bloodstain pattern analysts to observe bloodstaining on fabrics. Two of the most

common bloodstain patterns witnessed in such analyses are impact spatter stains and

transfer stains. Despite these patterns both being common occurrences at crime scenes,

they are created by very different mechanisms. Impact stains are generated when an

object strikes liquid blood. Conversely, a transfer stains is created when a bloodied object

comes into contact with a non-bloodied surface leaving blood residue on that surface. It

is important to differentiate between these stains because the confusion of impact and

transfer stains can lead to faulty conclusions and miscarriages in justice. This was clearly

illustrated in the David Camm case. In this case, the prosecution argued that 8 bloodstains

that were found on Camm’s shirt could only have been the result of an impact.

Conversely the defense argued that these stains were transfers and that they merely

appeared similar to impact stains. This experiment observed 406 transfer stain groups and

characterized each as either “identifiable transfer stains” or as “indistinguishable from

impact stains”. The result was that about 33% of the stain groups were labelled as

indistinguishable from impact stains. These results suggest that the differentiation of

impact and transfer based on individual stain characteristics should be avoided as the

potential for error is high.

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Acknowledgements

First I would like to thank my external supervisor, Dr. Brian Yamashita of the

RCMP, for suggesting the subject of my research as well for all of his guidance and

invaluable feedback during this work. Secondly I would like to thank my internal

supervisor and professor, Doctor Barry Saville for his guidance in writing this paper as

well as the very helpful feedback during this process. I would also like to thank Gord

Lefebvre of the Ontario provincial police for his advice and feedback throughout my

research. Next I would like to thank my professor Mike Illes for his advice and for

teaching me much about the field of bloodstain pattern analysis. I’d also like to thank the

other members of the RCMP for allowing me to work in their space and for offering

helpful advice. Lastly I would like to thank my fellow students for providing insightful

feedback that was invaluable to completing the project.

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Table of Contents

List of Figures .................................................................................................................... 6

List of Tables ...................................................................................................................... 7

Introduction ....................................................................................................................... 8

Materials and Methods. .................................................................................................. 14

Apparatus ................................................................................................................... 14

Sample Collection ...................................................................................................... 15

Pattern Creation .......................................................................................................... 16

Observation ................................................................................................................ 18

Results – Part One – Experimental Observations ........................................................ 20

Results – Part Two – Samples Sent to Bloodstain Pattern Analysts ........................... 25

Discussion ......................................................................................................................... 26

Overall Results ........................................................................................................... 26

Movement versus Non-Movement ............................................................................. 27

Additional Pressure in g/cm2 ...................................................................................... 28

Fabric Type ................................................................................................................ 29

External Bloodstain Pattern Analyst Results ............................................................. 31

Relevance ................................................................................................................... 32

Limitations and Future Research ............................................................................... 33

Conclusion ........................................................................................................................ 35

Literature Cited ............................................................................................................... 36

Appendices ....................................................................................................................... 38

Appendix A – Raw Data ............................................................................................ 38

Appendix B – Additional Photos of Apparatus and Tools Used ............................... 53

Appendix C – Photos of Sample Fabrics as Received ............................................... 53

Appendix D – VSC Images of Sample Groups Divided by Fabric Type, Pressure

Applied, and Whether Motion was Used ................................................................... 53

Appendix E – Result Sheets from External Bloodstain Pattern Analysts .................. 54

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List of Figures

Figure 1: Close-up of impact device and impact surface ................................................. 14

Figure 2: Mouse trap bloodspatter apparatus. .................................................................. 14

Figure 3: Diagram of the apparatus .................................................................................. 15

Figure 4: Fabric #1: Orange "Gigabytes" T-shirt (100% Polyester) ................................ 16

Figure 5 VSC Image of orange polyester shirt under natural lighting. 2.05X

magnification ..................................................................................................................... 18

Figure 6 VSC Image of orange polyester shirt under infrared lighting. 2.05X

magnification ..................................................................................................................... 19

Figure 7 VSC image of orange polyester shirt under infrared light at 18.17X

Magnification .................................................................................................................... 19

Figure 8 VSC image of orange polyester shirt under infrared light at 82.50X

Magnification. ................................................................................................................... 19

Figure 9: An example of an observably penetrated and symmetrical impact stain.. ........ 21

Figure 10: A transfer stain that could not confidently be distinguished from an impact

stain using the criteria discussed in the methods section.. ................................................ 21

Figure 11: A transfer stain that was identified as a transfer stain using the criteria

discussed in the methods section…………………………………………………………21

Figure 12: An identifiable transfer stain demonstrating saturation and destortion …..…21

https://d.docs.live.net/4a0b6c962be06873/Documents/Comparing%20Impact%20Spatter%20Stains%20versus%20Transfer%20Stains%20on%20Apparel%20Fabrics%20-%20FINAL%20VERSION%20(USE%20THIS%20ONE).docx#_Toc416330922
















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List of Tables

Table 1: The proportion of transfer stain groups that were identified as indistinguishable

from impact stains divided by whether lateral motion was applied during the transfer. ... 22

Table 2: The proportion of transfer stain groups that were identified as indistinguishable

from impact stains divided by what amount of pressure was applied during the transfer 23

Table 3: Table 3: The proportion of transfer stain groups that were identified as

indistinguishable from impact stains relative to the fabric on which the stains were

observed. ............................................................................................................................ 24

Table 4: Conclusions of the three volunteer bloodstain pattern analysts for each of the six

transfer stain images. ......................................................................................................... 25

Table 5: Conclusions of the three volunteer bloodstain pattern analysts for each of the

five impact statin images. .................................................................................................. 26

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Introduction

Bloodstain pattern analysis is the study of the shape, location, and distribution of

bloodstains and patterns of bloodstains in relation to crime (1). It is a sub-discipline of

forensic science and is supported by principles of chemistry, biology, and physics (2).

The methods of bloodstain pattern analysis are utilized in many forensic investigations,

especially those that involve violence. These methods are sometimes able to determine a

number of forces that may have been involved in an incident (3). Some of the information

that can be gained through the analysis of bloodstain patterns includes: the movement of

individuals during a crime, the sequencing of the events that occurred during a crime,

what objects were present at the crime scene or were removed from the crime scene, and

which individuals were present during a crime (1, 3). Practically, this information is used

to reconstruct the event of a crime, corroborate or refute witness statements, differentiate

between homicides and suicides, and direct the collection of DNA samples by identifying

areas with high likelihood of offender contact or movement (4). One example of such an

application was demonstrated in a case in which a bloodstain pattern analyst was able to

prove the victim’s death was the result of a homicide, and not a suicide as a ‘witness’ had

reported, by observing an absence of blood spatter on the victim’s hand (5). Such

deductions and applications are based largely on the biophysical properties of blood such

as its surface tension and internal cohesion and the assumption that blood droplets will

follow the laws of physics which allow for a degree of predictability that bloodstain

analysts must rely on during their studies (3). One of the largest criticisms regarding the

field of bloodstain pattern analysis is that it is subject to many sources of variability

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which have been under-researched and misapplied in the past (6). The effect of fabrics on

bloodstain pattern evidence is one of these under-researched variables.

Bloodstains on fabrics such as clothing are commonly discovered during the

analyses of many crime scenes and have the potential to make some very critical

indications such as the activities, positions, and levels of involvement of an individual at a

bloodletting event (7). For this reason it is critical that more research be conducted

regarding the variables involved in the formation of such stains (7). The importance of

such evidence can vary and can be critically relevant in cases where the accused states

that they were trying to aid the victim as an explanation for the presence of the victim’s

blood on their clothing (8). In such a case, the accused may argue that the stains on their

clothing were the result of transfers created when they were aiding the victim rather than

impact stains (9). The mechanisms for the formation of these two patterns are very

different. A transfer stain is generated by a blood-bearing surface coming into contact

with a non-blood covered surface whilst an impact stain pattern is generated by an object

striking liquid blood (10). The differentiation between these two types of stains can be

crucial to crime scene reconstruction. This is because impact stains tend to suggest that an

individual was present during, and in proximity to, a bloodletting while transfer stains

may originate any time after the bloodletting and do not necessarily indicate presence

during the bloodletting event (11). The correct differentiation between these patterns is

essential for discovering the truth of such matters, the failure to do so can have serious

consequences such as those that were observed in the David Camm Case.

The lack of research into how to differentiate between these stain types has led to

a number of court errors that have been costly in both time and resources and have also

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resulted in the conviction of innocent people (12,13). One prominent example of this is

the David Camm case in which a former Indiana state trooper, David Camm, was

suspected and eventually convicted of the murder of his wife and children (12). He came

under suspicion after 8 bloodstains were found on the shirt he was wearing during the

night of the murder. These 8 stains became the key pieces of evidence for the entire trial

(13). The prosecution argued that these stains were part of an impact pattern which would

have indicated that Camm was present during the bloodletting event and would therefore

be more likely to be guilty. Conversely, the defence argued that these stains were the

result of a transfer which could have occurred sometime after the bloodletting event and

thus could not indicate that Camm was more likely to be guilty. In the end, the defence

was unable to convince the jury that there was reasonable doubt and Camm was found

guilty (13). During this trial, the trial judge allowed a number of women to testify that

they had affairs with the accused which may have influenced the jury against Camm. This

was used to have the case dismissed but Camm was promptly recharged and convicted in

a second trial. The prosecutor of this trial alleged that Camm had sexually assaulted his

daughter which also proved to be false (12). Camm maintained his innocence for this

entire time and was finally released in 2013 after 13 years in prison and 3 trials that cost

the state of Indiana over 4.5 million dollars (12). This wrongful conviction and waste of

resources was not aided by the bloodstain pattern analysis, and perhaps if there had been

more research in differentiating between spatter stains and transfer stains on fabric

available to the analysts, this case could have been resolved correctly during the first trial.

With the above information in mind; the goal of this experiment was to determine

whether it is possible to differentiate between impact stains and transfer stains using only

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a few stains on a small region of fabric as they attempted to do in the Camm case. In other

words, can individual transfer stains and impact stains be differentiated from one another?

If it is shown that transfer stains can be distinguished from spatter stains based on the

discussed physical markers, then bloodstain analysts will be able to use these criteria to

corroborate or refute statements regarding these stains in court. Conversely, if it is

demonstrated that it there are times when it is not possible to differentiate spatter and

transfer under some conditions, then additional cautions can be implemented. The success

of this research should provide further information that will help prevent lengthy, and

expensive trials. It should also aid in the prevention of the conviction of innocent people

such as David Camm (12, 13).

A thorough literature review reveals a number of generally accepted criteria for

differentiating between impact stains and transfer stains. The criteria for impact stains

was found to include the stain being symmetrical, the pattern possessing a number of

secondary and tertiary droplets that result from the high speed with which the blood

impacts the surface, a zonal arrangement of the stains after drying including a central

zone with very little blood and outer zones with a lot more blood (4, 8, 11).

The literature also lists criteria for identifying transfer stains which include:

asymmetry of the stain or not having symmetrical projections, no real stain pattern or

zonal drying pattern, and may have a clear impregnation of material with blood(4,

8,11,14). These shared characteristics are commonly referred to as ideal forms. They do

not always apply as stains may deviate from such forms for a number of reasons that

include the angle of the surface, and the texture or material that they are deposited onto

(15,16).

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This distinction will be made using the above physical characteristics of these

individual stains including the degree to which the stain penetrates the weave of the

fabric, the symmetry of the stain, as well as the presence or absence of other stain

characteristics such as secondary spatter for impact stains and feathering or feathered

edges for transfer stains (4, 8, 11, 14).

In most circumstances, these types of bloodstain patterns are manageably

distinguished from one another but the determinations become somewhat more difficult

when the stains are on fabrics (8). This is because a fabric target surface changes a

bloodstain as it tends to absorb and distort blood that is deposited on it. (8). The shape and

size of a bloodstain that is generated on a fabric target surface is affected by a number of

characteristics of the fabric including its thread composition, the fabric’s porosity, its

absorbency, its age, and its treatment such as washings and stain resistance (11). Each of

these factors will have a different effect on the resulting stain. To make matters even

more complicated, each of these factors may be different between any two fabrics which

is why it is important to test any bloodstain patterns on multiple fabrics (4). These factors

may lead to misinterpretation in bloodstains on fabric if they are not completely

understood (9). This could include the mistaken identification of someone present at a

bloodletting event or a number of other faulty inferences regarding a bloodletting (8, 9).

Despite this, it is still believed that careful examination of bloodstained clothing

can provide useful information regarding the events of a crime (9). Spatter and transfer

may be misinterpreted when only individual stains are observed. From this, it can be

concluded that to successfully differentiate between such stains it is better to observe the

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overall appearance of stain patterns rather than individual stains. Such characteristics

include feathering for transfer stains, and central areas of origin for impact patterns (9).

The methods for this project were largely based on those used by Misty Holbrook

in her article, “Evaluation of Blood Deposition on Fabric: Distinguishing Spatter and

Transfer Stains” (11). Holbrook’s methods included creating spatter on eleven different

using one milliliter of blood and a rat trap to create the impacts. Pieces of fabric were

secured to a poster board target with a smooth surface to act as a control. The targets were

then allowed to air dry and the spatter was examined using a microscope. After that,

transfer stains were created on the same eleven fabrics using various items to produce the

stains. Each of these targets was then allowed to dry and they were examined

microscopically and compared to the spatter (11). The methods for this were designed in

an attempt to compare the physical traits of individual spatter stains and transfer stains

while controlling as many variables as possible. All of the procedures were performed on

multiple fabrics of different colours, materials, and weaves. This was done in an attempt

to assess the potential for transfer stains to possess the physical attributes of impact stains

and to determine what types of conditions will affect the frequency with which this

confusion occurs.

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Materials and Methods.

Apparatus

The apparatus for this experiment

was set up in a fume hood in the RCMP

forensic identification tower in Ottawa,

Ontario. The interior of the fume hood was

covered in brown paper to ensure easy clean

up. The actual impact device was a Victor-

brand mousetrap that was secured to the

base of the fume hood to prevent it from

moving between trials. A second, and

identical, mouse trap was placed in front of

this one to act as the impact surface as seen

in Figure 1. This was also secured with tape

and tape was also placed over the impact

surface to generate a smooth target and to

minimize the effect of the target surface

absorbance. These conditions allowed for easier cleanup and more reliably generated

impact patterns. Next, the target surface was placed on the back wall of the fume hood for

the blood to land on. This surface was then marked with a height scale in centimeters.

The fume hood cover was lowered during each impact to prevent blood from exiting the

apparatus. After assembling the apparatus, it was tested and found that the mechanism

produced an acceptable amount of spatter when the target surface was 15 cm high and the

Figure 1: Close-up of impact device and impact surface set perpendicular to one another so that they form area for blood to sit before being impacted

Figure 2: Image shows the two mouse traps set 90 degrees to one another.

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impact device was 10 cm from the

back wall of the fume hood.

Lastly, it was decided that a

volume of 100 µL of blood per

trial produced adequate stains so

this volume, measured using a

micropipette, was used for the

duration of the research.

Sample Collection

After the apparatus was prepared a variety of different sample fabrics were

collected and prepared. 21 samples were observed throughout the course of this

experiment, however, only information for 15 fabrics was recorded. The samples that

were eliminated were not used because they were either too similar to another sample in

composition or texture, or they did not yield any useful data. The 15 samples that were

recorded for use included:

1. Orange “Gigabytes” T-shirt – 100% Polyester

2. Denim Pants

3. Black Smart set long sleeve shirt (95% Cotton, 5% spandex)

4. Cops for cancer shirt (90% cotton,10% polyester)

5. Blue Striped bowling shirt (65% polyester, 35% cotton)

6. Red La vie est belle t-shirt (100% cotton)

7. Blue tag Cardigan (50% cotton, 50% acrylic)

8. Nylon socks

9. Flannel

10. Grey Dalhousie Hoodie (50% cotton, 50%polyester)

11. Grey pants (60% cotton, 40% polyester)

12. Brown Sheet (50% cotton 50 % polyester)

13. Socks (White w/grey bottoms (80% cotton + 17% Nylon +3% spandex)

Figure 3: Shows a diagram of the apparatus described here. The target surface being a height 15 cm above the fume hood floor, and a distance 10 cm from the blood source to the wall on which the target surface is attached.

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14. Blue dress shirt (wrinkle resistant) (60% cotton, 40% polyester)

15. Blue Silk Tie (100% Silk)

The samples were selected to represent a wide range of fabric compositions and types

to avoid drawing biased conclusions. After these samples were collected and

photographed, they were cut into sample pieces measuring approximately 15 x 10

centimeters. Each fabric had 11 such sample pieces cut from it in order to have the

number required to conduct the analysis. These 11 samples included one section for an

impact stain and 10 other sections prepared to receive transfer stains at varying pressures.

Some transfer stains were applied with motion and others without motion.

Pattern Creation

For the first two days the patterns in this experiment were performed using my

own blood which was extracted within two days of being used to generate a pattern and

was stored in a 2 mL vacuum blood collection tube and preserved with EDTA. The

purpose of the EDTA was to serve as an anticoagulant. It should also be noted that

previous experiments performed by

MacDonell et al. have concluded that

there were no observed differences in

the physical behaviours of blood that

had been preserved with anticoagulants

such as EDTA and blood that was

freshly drawn from the body (17). After

the first two days of the experiment the

blood used was sheep’s blood. This practice is common practice for bloodstain pattern

analysts as it has been demonstrated that the physical differences between sheep’s blood

Figure 4: Fabric #1: Orange "Gigabytes" T-shirt (100% Polyester)

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and human blood are negligible (18). Overnight, the blood was stored in a refrigerator

which kept the blood at -4 degrees Celsius. The sample was always incubated at room

temperature for 10-15 minutes to give it time to reach room temperature before it was

used in pattern generation. Before the samples were analyzed, a control card was made

for each type of blood pattern to act as reference for patterns found on clothing. The first

pattern that was generated for each sample was the impact pattern. The target sample was

placed directly on the back wall of the fume hood at a height of 15 centimetres and 10

centimetres from the impact device. Impact spatter was generated by pulling the

mousetrap bar all the way back and then allowing it to impact the 100 µL of blood placed

on the impact surface with the same force in each trial. The sample was then removed

from the wall and placed on a clean flat surface to dry before being analyzed. The device

was thoroughly cleaned after each use to generate consistent spatter and minimize

interference.

The transfer patterns for the samples were created after their respective impact

patterns. The transfer patterns were created by first generating an impact pattern on a

clean glass slide using the same method as above and then pressing the sample fabric

against it immediately for the transfer. This was done by setting the fabric on top of the

glass slide with the beaker filled with water on top of the fabric. The glass slide was used

because it was a smooth surface that was easy to clean between trials. Multiple transfers

were made on each of the sampled fabrics whilst using different weights generated using

water in a beaker to simulate differing pressures and alternating between transfers in

which the non-bloodied object moved across the blood source with the filled beaker on

top of it and transfers in which the non-bloodied object was simply pressed onto the blood

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with the filled beaker set on top of it. It should be noted that a new impact pattern was

created on a clean slide before each transfer. These conditions were altered in turn to view

their impact on the shape of the transfer stains, and to observe whether they generated

transfer stains that were more similar to impact stains. The masses used were 0g, 50g,

100g, 400g, and 1000g and were altered by the addition of different volumes of water into

beakers placed on top of the fabric. This was done so the mass could be altered and

checked. The masses for these beakers were checked after each trial to ensure constant

conditions. These masses were used to calculate the pressure that was applied to the

samples. This was done by measuring the mass of the water and the beaker as described

above and then dividing it by the surface area of the bottom of the beaker. The pressures

were calculated by this method because the beakers were placed on top of the fabrics

during the transfer so the weight would be distributed evenly across the bottom of the

beaker. These pressures were calculated as 0 g/cm2, 3.144g/cm2, 6.017g/cm2, 9.82g/cm2,

and 14.11 g/cm2 relative to the masses of 0g, 50g, 100g, 400g, and 1000g.

Observation

After all of the stains were created, they

were observed using a video spectral comparator,

specifically the VSC 5000, which is capable of

viewing the fabrics at multiple different

magnifications as well as generating infrared light

which is useful for viewing stains on darker or

coloured fabrics. The enhanced visibility is the

Figure 5 VSC Image of orange polyester shirt under natural lighting. 2.05X magnification according to VSC

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result of blood absorbing most wavelengths of

infrared light while the dyes used for clothing tend

to reflect it. For the samples that required the use

of infrared light, a 608 band-pass setting was used.

The band-pass number refers to the wavelength of

light that is allowed through the filter (19, 20).

This results in the apparel having a white

appearance while the bloodstain tends to have a

darker colour (See Figures 6-8) (19, 20). The

general procedure for observing the patterns using

the VSC was to first view them at a lower

magnification, 2X to 3X, and then focus on

individual stains at a higher magnification, 30-

45X, and finally view individual stains at 80-85X.

The determination of whether a stain was an

impact stain or a transfer stain was made based on

three main characteristics. The first of these

characteristics is the degree to which the stain has

penetrated into the fabric. An impact stain will

usually have enough kinetic energy to penetrate to

the lower layers of a fabric while a transfer stain

will usually just rest atop the weave an Figure 9

shows an example of a stain that has observably penetrated the weave of the

Figure 6 VSC Image of orange polyester shirt under infrared lighting. 2.05X magnification according to VSC

Figure 7 VSC image of orange polyester shirt under infrared light at 18.17X Magnification according to the VSC software

Figure 8 VSC image of orange polyester shirt under infrared light at 82.50X Magnification according to the VSC software.

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fabric(13,14). The second factor to consider is

the symmetry of the stain as impact spatter

stains will tend to be symmetrical much more

frequently than transfer stains. Figure 9 is also

an example of an observably symmetrical

stain (13,14). Finally each stain was observed

for the presence of feathered edges which was

considered a characteristic of transfer stains.

Figure 11 is an example of a transfer stain

with feathered edges. In addition to these criteria, the transfer stains were compared to the

stains of an impact pattern on the same material in an attempt to account for that variable.

After producing the patterns, some photographs were sent to a number of bloodstain

analysts with instructions to use these criteria in an attempt to see whether they would be

able to correctly differentiate between impact stains and transfer stains using only a few

stains. This process of observation was applied to each of 406 transfer stain groups while

the impact stains were used as controls for each fabric type. Then each of these transfer

stain groups were identified as either “identifiable transfer stains” or as indistinguishable

from impact stains. The stain groups were identified as one to nine individual stains in

close proximity to one another. The number of stain groups varied for each transfer

samples.

Results – Part One – Experimental Observations

This investigation has found that 135 of 406, or about 33%, of the observed

transfer stain groups were characterized as indistinguishable from the impact stains that

Figure 9: An observably penetrated and symmetrical impact stain. Found on Fabric six and viewed at 82.50X magnification according to VSC 5000.

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were generated on the same fabric. An example of such a stain can be seen in Figure 9

below. Conversely, 271 of 406, or about 67%, of the transfer stain groups were

characterized as “identifiable transfer stains”. An example of this characterization is

demonstrated in Figure 10 below.

The summary data can be divided in relation to the variables that were observed.

These include: whether the transfers were conducted while applying lateral motion or

without applying lateral motion, what amount of pressure was applied during this transfer,

and what type of fabric was being tested. Table 1 illustrates the proportions of stain

Figure 11: From Fabric #5, the Blue Striped bowling shirt (65% polyester, 35% cotton). Was generated with lateral motion and with 6.017g/cm2 of pressure applied. It shows a transfer stain that was identified as a transfer stain using the criteria discussed in the methods section. Viewed at 18.17X magnification according to the VSC 5000.

Figure 10: From Fabric #5, the Blue Striped bowling shirt (65% polyester, 35% cotton). Was generated with lateral motion and with 3.144g/cm2 of pressure applied. It shows a transfer stain that could not confidently be distinguished from an impact stain using the criteria discussed in the methods section. Viewed at 18.17X magnification according to the VSC 5000.

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groups that were found to be indistinguishable from impact stains relative to whether the

transfer was conducted with lateral motion or without such a motion.

Table 1: Shows the proportion of transfer stain groups that were identified as

indistinguishable from impact stains transferred with and without motion.

Stain Groups

Observed

Transfer Stain Groups

Indistinguishable from Impact Stains

Percentage of

Indistinguishable Stains

Non

Motion

206 83 40

With

Motion

200 52 26

Table 1 demonstrates that the transfer stain groups that were made without motion

were more likely to be indistinguishable from impact stains created on the same fabric

type. Next, Table 2 illustrates the proportions of stain groups that were found to be

indistinguishable from impact stains on the same fabric relative to the amount of pressure,

in grams per square-centimeter, which was applied to the fabric as the transfer was being

conducted.

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indistinguishable from impact stains divided by what amount of pressure was applied

during the transfer.

Pressure

(g/cm2)

Stain Groups

Observed


Indistinguishable from Impact

Stains

Percentage of


0 48 18 38

3.144 82 31 38

6.017 87 26 30

9.82 87 31 36

14.11 102 29 28

Table 2 shows that increased pressure resulted in an increased number of

observable stain groups. There were 48 observable stain groups with no added pressure

and 102 observable stain groups with 14.11 g/cm2 of added pressure. There was not an

observable relationship between the amount of pressure added during the transfer stain

creation and the proportion of stains that could not be differentiated from impact stains on

the same fabric. Finally Table 3 notes the proportion of transfer stain groups that were

found to be indistinguishable from impact stains divided based on which fabric the stain

group was found.

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indistinguishable from impact stains relative to the fabric on which the stains were

observed.

Clothing Stain

Groups

Observed


Indistinguishable from

Impact Stains

Percentage of


Fabric One - 100%

Polyester Shirt

32 14 44

Fabric Two - Blue

Denim Jeans

23 5 22

Fabric Three - 95%

Cotton, 5% Spandex

22 6 27

Fabric Four - 90%

Cotton, 10% Polyester

29 11 38

Fabric Five - 65%

Polyester, 35% Cotton

37 13 35

Fabric Six - 100%

Cotton

34 5 15

Fabric Seven- 50%

Cotton, 50% Acrylic

3 1 33

Fabric Eight - Nylon

Socks

31 6 19

Fabric Nine - Flannel

Material

35 19 54

Fabric Ten - 50%

Cotton, 50%Polyester

29 13 45

Fabric Eleven - 60%


9 3 33

Fabric Twelve - 50%

Cotton 50 % Polyester

23 3 13

Fabric Thirteen - 80%

Cotton + 17% Nylon

+3% Spandex

44 12 27

Fabric Fourteen - 60%


38 18 47

Fabric Fifteen - 100%

Silk

17 6 35

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According to Table 3, the fabrics with the highest proportions of transfer stains

that weren’t differentiated from impact stains on the same fabric were Fabric One with

44%, Fabric Nine with 54%, Fabric Ten with 45%, and Fabric Fourteen with 47%.

Conversely the fabrics with the lowest proportions of indistinguishable stains were Fabric

Twelve with 13%, Fabric Six with 15%, Fabric Eight with 19%, and Fabric Two with

22%.

Results – Part Two – Samples Sent to Bloodstain Pattern Analysts

The tables below illustrate the results of 11 sample photos each being sent to three

bloodstain pattern analysts who were given the instructions to identify each stain as either

impact, transfer, or undetermined. Six of these photos depicted transfer stains while the

remaining five depicted impact stains.

Table 4: Shows the conclusions of the three volunteer bloodstain pattern analysts for each

of the six transfer stain images which can be found in Appendix E.

Transfer stain

groups

Identified as

Impact

Identified as

Transfer

Undetermined

Sample C 0 0 3

Sample D 0 0 3

Sample E 0 0 3

Sample F 0 0 3

Sample G 0 1 2

Sample H 0 2 1

Table 4 shows that the analysts would only identify three out of 18 of the sampled

images as transfer stains. The other 15 stain groups, or 83% of the stain groups, did not

fulfill their criteria for either impact or transfer and were labelled “undetermined”.

26

Table 5: Shows the conclusions of the three volunteer bloodstain pattern analysts for each

of the five impact statin images which can be found in Appendix E.

Impact Stain

Groups

Identified as

Impact

Identified as

Transfer

Undetermined

Sample A 0 2 1

Sample B 0 0 3

Sample I 0 0 3

Sample J 0 0 3

Sample K 0 0 3

Table 5 shows that none of the impact stain photographs that were sent to the

analysts were identified as impact stains and in fact, two of them were identified as

transfer illustrating the potential for impact stains to appear the same as transfer stains.

Discussion

Overall Results

Of the 406 transfer stain groups that were observed over the course of this thesis,

it was found that 135 of them could not be confidently distinguished from the impact

stains that were created on the same fabric type based on their individual physical

characteristics. This number represents about 33% of the stain groups that were observed.

This data demonstrates that there is potential for transfer stains to appear the same as

impact stains and suggests that care must be taken when observing such stains based on

their individual stain traits as there is an increased potential of incorrect stain

identification. In an attempt to identify some factors that were involved in transfer

appearing to be impact, the results were divided and reported based on the conditions that

were used to create the samples.

27

Movement versus Non-Movement

The first way in which the results were divided was by whether the transfer was

conducted with lateral motion or without such a motion as seen in table 2. It was observed

that about 40.3% of the 206 stain groups that were created without lateral motion during

the transfer were found to be indistinguishable from the impact stains that were created on

the same fabric types. Conversely, only 26% of the 200 transfer stain groups that were

created by laterally moving the sample over the blood were found to be indistinguishable

from the impact staining on the same fabric. These results are easily explainable and

actually unsurprising. The key reason that the transfers which made with lateral motion

were more identifiable as transfer was that the application of motion in transfer is the

mechanism that causes feathering. Recall, that feathering is the presence of feathered or

faded edges on a stain and that it is one of the key traits that were used to confidently

identify stains as transfer (14). Since the stains that were created without motion were

much less likely to demonstrate feathering. That meant that they had one less feature to

distinguish them from impact stains which led to more easily confused conclusions. In

contrast to this, the stains that were created with lateral motion were more likely to

possess feathered edges and were more easily identified as transfer stain. A second factor

that likely increased the amount of indistinguishable stain groups for the transfers that

were created without motion was that the lack of motion made it so the appearance of the

initial pattern being transferred was preserved on the resulting transfer stains. Since the

initial pattern in this experiment was an impact pattern, it is unsurprising that a direct

transfer such as this would result in stain groups that could not be easily differentiated

from impact stains. This is especially true because the glass slide that was used in the

28

transfer was smooth and non-porous meaning that it did not alter the shape of the impact

stains before the transfer. An additional reason that the transfer stains created without

lateral motion during the transfer were harder to distinguish from impact stains was that

the lack of motion resulted in the blood being more easily absorbed by the fabric. This

increased absorption appeared similar to the penetration that is characteristic of impact

stains. So from this data, it is concluded that small transfer stains that are created without

motion are more difficult to differentiate from impact stains than transfers of the same

size.

Additional Pressure in g/cm2

A second variable that could have had some effect on the odds of transfer stains

appearing to have the physical characteristics of impact was the amount of additional

pressure that was applied to the samples during the transfer. The five different pressures

that were used in this study were 0g/cm2, 3.144g/cm2, 6.017g/cm2, 9.82g/cm2, and

14.11g/cm2 as seen in table 3. One trend that was observed for this set of criteria was that

the transfers that were made with higher amounts of pressure resulted in more observable

stains than the fabrics that received little or no added pressure. To quantify this, there

were 48 observable stain groups created across all the samples that were made with no

added pressure while the samples that were made with an additional 14.11g/cm2 had a

collective 102 observable stain groups. This trends indicates that increased weight applied

during the transfer resulted in a higher number of observable stains. It was also expected

that a higher amount of pressure being applied to the sample during the transfer creation

would result in a higher proportion of transfer stains that could not be distinguished from

impact stains on the same material. It was thought that the increased force pushing the

29

blood into the fabric would mimic the penetration observed for impact stains. These

expectations were incorrect. After collecting the data, it was found that there was no

observable relationship between the amount of pressure that was applied during the

transfer pattern creation and the number of stain groups that could not be distinguished

from impact stains created on the same fabric. In fact it was observed that the transfers

that were made with 14.11 g/cm2 of added pressure were most frequently found to be

easily identifiable transfer stains. This could

have been because the increased pressure

caused distortion and saturation that is not

characteristic of impact stains in a number of

the observed fabrics. An example of such a

stain can be observed in Figure 12.

However, with that said there were really no

observable trends in the pressure applied

versus the proportion of indistinguishable

stains.

Fabric Type

The last variable assessed was the type of the fabric on which the transfers were

created. After separating the data based on fabric type, as seen in Table 4, it was found

that the fabric type did have an effect on the ability to confidently distinguish the transfer

stains from impact stains. More specifically, fabric six, fabric eight, and fabric twelve had

more transfer stain groups that were easily identified as transfer stains than the other

fabrics. Only around 14.7% of the stain groups that were observed on fabric six, the 100%

Figure 12: An identifiable transfer stain that was created with 14.11g/cm2 of added pressure. Found on fabric 5 and viewed with 18.17X magnification according to VSC 5000.

30

cotton “la vie est belle” shirt, were not differentiated from the impact stains that were

created on the same fabric. Similarly, 19.4% of the transfer stain groups that were created

on fabric eight, the nylon sock fabric, weren’t differentiated from the impact stains.

Lastly, fabric twelve, the 50% cotton-50%polyester blended brown sheet, had only 3 out

of 23 or 13% of the stains observed that could not be distinguished from the impact stains

created on the same fabric. In opposition to this: fabric one, fabric nine, fabric ten, and

fabric 14 each had a high amount of stains that could not be differentiated from the

impact stains on the same fabric. Fabric one, the 100% polyester orange “gigabytes” shirt,

possessed 14 out of 32 stains, or 43.75%, that could not be confidently identified as

transfer when compared to the impact stains that were created on the same material.

Similarly, 54.3% of the stain groups that were observed on the flannel material could not

be distinguished from impact stains on the same fabric. Fabric ten, the 50% polyester-

50% cotton blended sweater, had 44.8% or 13 of 29 transfer stain groups that could not be

confidently identified as transfer stains. Lastly, 47.3% of the stain groups that were

observed on fabric fourteen, the blue wrinkle resistant dress shirt, were not confidently

identifiable as transfer stains to the exclusion of the impact stains on the same fabric.

With this information, it can be concluded that the fabric on which the transfer pattern is

created does have an effect on the number of transfer stain groups that may be confused

for impact stains based on their physical attributes. This is especially apparent in

observing the difference between fabric nine and fabric six. The difference between the

total stain groups observed for these fabrics was only one with fabric nine having a

sample size of 35 compared to fabric six’s sample size of 34. Despite this small difference

in sample size, it was found that 19 of the stain groups for fabric nine were

31

indistinguishable from impact stains while only 5 stain groups for fabric six were found to

be indistinguishable impact stains. This marked difference in indistinguishable transfer

stain groups despite similar sample size illustrates the effect that fabric type has on the

interpretation of these transfer stains. Unfortunately, it is not possible to make any

specific conclusions about which fabric types had what effect on the stains due to the

limited sample information and because samples of the same fabric type had differing

results. A clear illustration of this is the difference between the percentage of

indistinguishable stains between fabric ten and fabric twelve which were both 50% cotton

– 50%polyster blends. Fabric ten had 44.8% of its stain groups identified as

indistinguishable from impact spatter stains while fabric twelve had only 13% of its stain

groups identified as indistinguishable from its respective impact stains. One potential

reason for this marked difference could be the different fabric weaves. For instance, more

tightly weaved fabrics could be less likely to have stains penetrate than clothing with a

looser weave. Additionally, newer clothing will likely allow less penetration of stains

than older and more worn clothing for the same reason. Thus, by separating the data

based on fabric type, it has been demonstrated that the surface on which the transfers

were created effected the proportion of indistinguishable stains.

External Bloodstain Pattern Analyst Results

Three volunteer bloodstain pattern analysts attempted to identify 6 transfer stain

photographs as either impact stains, transfer stains, or undetermined. This resulted in a

total of 18 determinations. Of these, only 3 determinations identified these transfer stains

as transfer while the other 15 labelled them as undetermined. This would seem to indicate

that there is difficulty in confidently labelling transfer stains on fabric. However, this may

32

have been influenced by the fact that these analysts were only able to observe

photographs of the stain groups rather than analyze the samples themselves. This likely

increased the amount of “undetermined” determinations. This possibility is supported by

the results of the volunteer analysts observing the impact stains in which 13 of the 15

determinations were labelled as undetermined. These results suggest a reluctance of the

bloodstain analysts to make definitive conclusions regarding the images which indicates

that the images were largely not sufficient for them to make such conclusions.

Relevance

These results are important because it must be known that there is the potential for

transfer stains to appear the same as impact stains on the same fabric. Since it is a

common request for bloodstain pattern analyst to observe bloodstains on fabric, being

aware of this potential confusion should lead to greater caution being applied to

determinations made based on the physical characteristics of individual stains (13). It is

important that differentiating between impact and transfer stains be done correctly

because the mechanisms that cause these stains are very different and are used to

demonstrate different things. Impact stains are created by an object striking liquid blood

and generally indicates that an individual was present during a blood-letting event.

Conversely, transfer stains are created when a blooded object contacts a non-blooded

surface, and this does not require that the sample be present during a blood-letting event

but merely to come into contact with the blood afterwards. Thusly, the misidentification

of a transfer stain on an article of clothing as an impact stain could lead to a false

implication that an individual wearing that clothing was present at a scene during a blood-

letting event. Such an incident may have been observed in the David Camm trials (12,13).

33

For this reason it is important to be aware that transfer stains may mimic the appearance

of impact stains and that the chances of this occurring are influenced by a number of

factors

Limitations and Future Research

There are a number of limitations that should be noted regarding this experiment.

First of all it should be noted that the transfer patterns of this experiment stains were

created using an impact pattern as the source pattern. The use of an impact pattern in the

transfer pattern creation unsurprisingly increases the potential for confusion of the

transfer stains for impact. This is especially true as a clean glass slide was used as the

bloodied object in the transfer. The glass slide was an ideal surface to maintain the shape

of the impact stains during the transfer as it does not have any characteristics that would

distort the stains before the transfer was conducted. Thus it should be noted that the high

proportions of unidentifiable stains are the result of an idealized set of conditions for

creating transfer that mimics impact. It is reasonable to expect that most stains collected

at actual crime scenes will be more easily differentiated from impact stains than the ones

created for the purposes of this study.

A second limitation of this procedure was that only 15 different fabrics were

observed. This sample size was sufficient to demonstrate that the surface that the transfer

stains were created on did have an effect on how difficult it was to distinguish the

resulting transfer stain groups from impact stains. However 15 sample fabrics was

insufficient to comment on any trends regarding how specific fabric compositions

effected the difficulty of differentiating the transfer stains from impact stains. For this

34

reason, one suggestion for future research is to conduct the same methods on additional

fabrics.

A third potential limitation of this experiment were the tools that were available to

me. The video spectral comparator was useful for its ability to emit infrared light (20).

The use of infrared light provided the ability to observe stains on darker fabric more

clearly but one issue with it was that it did not provide as high of a resolution as some

other microscopes. This decrease in resolution made it more difficult to determine

whether a stain had penetrated the fabric or whether it was sitting on the top layer and

made differentiation of the transfer and impact stains more difficult. For this reason, it

would be a good idea to conduct this experiment again with a microscope capable of

higher resolution imaging.

A final limitation of this experiment is that the analysis of the stain groups was

conducted by the same person who created them. Since I knew that all of the stain groups

I was observing were the result of transfer, it could have led to a bias towards identifying

them as transfer. It is worth noting that this variable was attempted to be corrected by

sending the photos of some impact stains and some transfer stain groups to the bloodstain

pattern analysts. This was done to observe whether they would make the same

conclusions. However, it should also be noted that the sample number sent to these

analysts was much smaller than the sample number that was observed during the

experiment. It would have been ideal to send all of the samples that were observed but it

was not practical to do so. Additionally, these analysts were only provided with

photographs which could have had an effect on their ability to properly analyze the

samples.

35

Conclusion

From the experiments carried out it was determined that there is a potential for transfer

stains to share the physical characteristics of impact stains under certain conditions. It was

found that transfer stains created without lateral motion during the transfer were more

likely to be clearly identifiable as transfer stains and that the fabrics on which these stains

are created is also a relevant factor. With this in mind, it is recommended that the

differentiation of impact stains and transfer stains based on individual stain characteristics

should be avoided as the potential for error is high. Instead the appearance of individual

stains should be considered together with the characteristics of the fabric on which they

are deposited and the factors of the specific case. These findings are consistent with

existing literature such as Misty Holbrook’s article, “Evaluation of Blood Deposition on

Fabric: Distinguishing Spatter and Transfer Stains” in which she found that it was easy to

create spatter and transfer stains that mimicked one another and concluded that

“consideration must be given to the quantity of stains and their distribution” and that

“making the distinction between spatter and transfer stains on items of clothing should be

done with caution”(11).

36

Literature Cited

1. Bevel T, Gardner RM. Bloodstain pattern analysis with an introduction to crime

scene reconstruction. 3rd ed. CRC Press, London: 2008.

2. Joris P, Develter W, Jenar E, Suetens P, Vandermeulen, D, Voorde WV, Claes

P. Calculation of bloodstain impact angles using an active bloodstain shape

model. J Rad For Imag. 2014 October, 2(4): 188-98.

3. Brodbeck S. Introduction to bloodstain pattern analysis. J Pol Sci Pract.

2012;2(1):51-57.

4. James SH, Kish PE, Sutton P. Principles of bloodstain pattern analysis: theory

and practice. 1st ed. 2005 May.

5. https://sites.google.com/site/bloodspatteranalysisforensics/4-case-study.

6. The National Academy of Sciences Report on Forensic Sciences. National

Research Council. 2009 Aug;1(1).

7. White B. Bloodstain patterns on fabrics: the effect of drop volume, dropping

height and impact angle. 1986 Feb; 19(1).

8. De Castro T, Nickson T, Carr D, Knock C. Interpreting the formation of

bloodstains on selected apparel fabrics. Int J Legal Med. 2013 Jan; 127(1):251-

8.

9. Slemko, J. Bloodstains on Fabrics, IABPA News, 2003; 19(4):3-11

10. SWGSTAIN, scientific working group on bloodstain pattern analysis:

recommended terminology. IABPA Newsletter 2008 June; 1(1).

11. Holbrook M. Evaluation of blood deposition on fabric: distinguishing spatter

and transfer stains. IABPA News. 2011 March;26(1):3-12.

12. Indiana v. David Camm, 812 N.E.2d 1127 (Ind. App., 2004).

13. Possley M. David Camm. The National Registry of Exonerations. 2013 Oct 25.

14. Peschel O, Kunz SN, Rothschild MA, Mutzel E. Blood stain pattern analysis.

Forensic Sci Med Pathol 2011 Sept; 7(1):257-70.

15. Connolly C, Milles M, Fraser J. Effect of impact angle variations on area of

origin determination in bloodstain pattern analysis. For Sci Int. 2012 Nov;

223(1-3):233-40.

37

16. Laber T, Kish P, Taylor M, Owen G, Osborne N, Curran J. Reliability

assessment of current methods in bloodstain pattern analysis. National Institute

of Justice. 2014 Jun;1(1).

17. MacDonell, H.L., Interpretation of Bloodstains: Physical Considerations, Legal

Medicine Annual, Wecht, C., Ed., Appleton, Century Crofts, New York, 1971,

pp. 91–136.

18. Christman DV. A study to compare and contrast animal blood to human blood

product. IABPA News. 1996; 12(2):10-25.

19. Gorn M, James SH. Using infrared photography to document clothing evidence

in the reconstruction of a homicide. IABPA Newslettter 2013 Dec;28(4):3-9.

20. Aambe M. Use of the “Video Spectral Comparator 6000” as a non-destructive

method for pigment identification. University of Gothenburg. May 2011

38

Appendices

Appendix A – Raw Data

Fabric One – With Motion

Table 6: Shows the amount of transfer stains that were found to be indistinguishable from

impact stains for transfers with motion for fabric #1: 100% polyester.

Pressure

(g/cm2)

Stain Groups Observed Transfer Stain Groups


Impact Stains

Percentage of

Indistinguishable

Stains

0 1 0

3.144 5 2

6.017 3 0

9.82 2 0

14.11 4 1

Total 15 3 20

Fabric One – Without Motion


impact stains for transfers without motion for fabric #1: 100% polyester.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 3 3

3.144 5 4

6.017 3 2

9.82 3 1

14.11 3 1

Total 17 11 65

39

Fabric Two – With Motion


impact stains for transfers with motion for fabric #2: Blue denim jeans.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 2 0

3.144 1 1

6.017 2 1

9.82 2 1

14.11 3 0

Total 10 3 30

Fabric Two – Without Motion


impact stains for transfers without motion for fabric #2: Blue denim jeans.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 4 0

3.144 2 0

6.017 3 0

9.82 1 1

14.11 3 1

Total 13 2 15

40

Fabric Three – With Motion

Table 10: Shows the amount of transfer stains that were found to be indistinguishable

from impact stains for transfers with motion for fabric #3: 95% cotton, 5% spandex.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 2 0

6.017 3 1

9.82 3 0

14.11 2 0

Total 10 1 10

Fabric Three – Without Motion


from impact stains for transfers without motion for fabric #3: 95% cotton, 5% spandex.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 1 0

6.017 3 0

9.82 3 2

14.11 5 3

Total 12 5 42

41

Fabric Four – With Motion


from impact stains for transfers with motion for fabric #4: 90% cotton, 10% polyester.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 3 2

3.144 2 1

6.017 3 0

9.82 3 0

14.11 3 0

Total 14 3 21

Fabric Four – Without Motion


from impact stains for transfers without motion for fabric #4: 90% cotton, 10% polyester.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 1

3.144 4 4

6.017 2 1

9.82 4 2

14.11 4 0

Total 15 8 53

42

Fabric Five – With Motion


from impact stains for transfers with motion for fabric #5: 65% polyester, 35% cotton.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 2 2

3.144 3 0

6.017 4 1

9.82 4 0

14.11 5 2

Total 18 5 28

Fabric Five – Without Motion


from impact stains for transfers without motion for fabric #5: 65% polyester, 35% cotton.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 3 2

3.144 4 2

6.017 4 0

9.82 4 2

14.11 4 2

Total 19 8 42

43

Fabric Six – With Motion


from impact stains for transfers with motion for fabric #6: 100% cotton.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 3 1

3.144 3 0

6.017 2 0

9.82 4 0

14.11 5 0

Total 17 1 6

Fabric Six – Without Motion


from impact stains for transfers without motion for fabric #6: 100% cotton.

Pressure

(g/cm2)



Impact Stains

Percentage of

Indistinguishable

Stains

0 2 0

3.144 3 1

6.017 5 3

9.82 3 0

14.11 4 0

Total 17 4 24

44

Fabric Seven – With Motion


from impact stains for transfers with motion for fabric #7: 50% cotton, 50% acrylic.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 3 1

6.017 0 0

9.82 0 0

14.11 0 0

Total 3 1 33

Fabric Seven – Without Motion


from impact stains for transfers without motion for fabric #7: 50% cotton, 50% acrylic.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 0 0

6.017 0 0

9.82 0 0

14.11 0 0

Total 0 0 N/A

45

Fabric Eight – With Motion


from impact stains for transfers with motion for fabric #8: Nylon Socks.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 2 0

3.144 4 1

6.017 1 0

9.82 5 1

14.11 4 0

Total 16 2 13

Fabric Eight – Without Motion


from impact stains for transfers without motion for fabric #8: Nylon Socks.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 0

3.144 5 2

6.017 3 0

9.82 3 2

14.11 3 0

Total 15 4 27

46

Fabric Nine – With Motion


from impact stains for transfers with motion for fabric #9: Flannel Material.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 5 0

6.017 4 4

9.82 3 2

14.11 4 2

Total 16 8 50

Fabric Nine – Without Motion


from impact stains for transfers without motion for fabric #9: Flannel Material.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 0

3.144 4 3

6.017 4 2

9.82 5 4

14.11 5 2

Total 19 11 58

47

Fabric Ten – With Motion



Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 0 0

6.017 7 3

9.82 3 0

14.11 4 1

Total 14 4 29

Fabric Ten – Without Motion


from impact stains for transfers without motion for fabric #10: 50% cotton, 50% polyester

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 1

3.144 3 3

6.017 2 0

9.82 4 2

14.11 5 3

Total 15 9 60

48

Fabric Eleven – With Motion



Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 1

3.144 1 0

6.017 1 1

9.82 3 0

14.11 3 1

Total 9 3 33

Fabric Eleven – Without Motion


from impact stains for transfers without motion for fabric #11: 60% cotton, 40%

polyester.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 0 0

6.017 0 0

9.82 0 0

14.11 0 0

Total 0 0 N/A

49

Fabric Twelve – With Motion



Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 3 1

6.017 2 1

9.82 3 1

14.11 3 0

Total 11 3 27

Fabric Twelve – Without Motion



polyester.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 0

3.144 3 0

6.017 4 0

9.82 2 0

14.11 2 0

Total 12 0 0

50

Fabric Thirteen – With Motion


from impact stains for transfers with motion for fabric #13: 80% cotton, 17% nylon, 3 %

spandex.

Pressure

(g/cm2)

Stain Groups

Observed



Stains

Percentage of

Indistinguishable

Stains

0 3 0

3.144 3 0

6.017 5 1

9.82 4 1

14.11 4 1

Total 19 3 16

Fabric Thirteen – Without Motion


from impact stains for transfers without motion for fabric #13: 80% cotton, 17% nylon,

3% spandex.

Pressure

(g/cm2)

Stain Groups

Observed



Stains

Percentage of

Indistinguishable

Stains

0 6 2

3.144 3 2

6.017 5 2

9.82 5 2

14.11 6 1

Total 25 9 36

51

Fabric Fourteen – With Motion



Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 4 3

3.144 6 1

6.017 5 1

9.82 5 3

14.11 5 3

Total 25 11 44

Fabric Fourteen – Without Motion



polyester.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 1 0

3.144 2 1

6.017 3 2

9.82 4 2

14.11 3 2

Total 13 7 54

52

Fabric Fifteen – With Motion


from impact stains for transfers with motion for fabric #15: 100% silk.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 0 0

3.144 0 0

6.017 1 0

9.82 1 1

14.11 1 0

Total 3 1 33

Fabric Fifteen – Without Motion


from impact stains for transfers without motion for fabric #15: 100% silk.

Pressure

(g/cm2)



Stains

Percentage of

Indistinguishable

Stains

0 3 0

3.144 2 1

6.017 3 0

9.82 1 1

14.11 5 3

Total 14 5 36

53

Appendix B – Additional Photos of Apparatus and Tools Used

Refer to included DVD under folder “Appendix B – Additional Photos of Apparatus and

Tools Used”

Appendix C – Photos of Sample Fabrics as Received

Refer to included DVD under folder “Appendix C – Photos of Sample Fabrics as

Received”. It is noted that the image for fabric 5, the 65% polyester and 35% cotton

blended blue-striped bowling shirt, was corrupted and could not be included in this

appendix.

Appendix D – VSC Images of Sample Groups Divided by Fabric Type, Pressure

Applied, and Whether Motion was Used

Refer to included DVD under folder “Appendix D – VSC Images of Sample Groups

Divided by Fabric Type, Pressure Applied, and Whether Motion was Used”

54

Figure 13: The top image shows an impact stain that was created of Fabric 14 while the bottom image shows an impact stain that was created on fabric 15.

Appendix E – Result Sheets from External Bloodstain Pattern Analysts

55

Figure 14: The top image is a transfer stain that was created without motion and with 9.82g/cm2 of additional pressure on Fabric 5. The bottom image is a transfer stain that was created without motion and with 9.82g/cm2 of additional pressure on Fabric 4

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Figure 15: The top image shows a transfer stain that was created without motion and with an added 9.82g/cm2 of pressure on Fabric 13. The bottom image shows a transfer stain that was created with motion with 14.11g/cm2 of additional pressure on Fabric 14.

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Figure 16: The top image shows a transfer stain that was created without motion and with 6.017g/cm2 of added pressure on Fabric 13. The bottom image shows a transfer stain that was created with motion and with 9.82g/cm2 of added pressure on Fabric 8.

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Figure 17: The top image is an impact stain that was created on Fabric 4 while the bottom image was an impact stain that was created on Fabric 5.

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Figure 18: This shows impact stains that were created on Fabric 1.

Date post:	12-Apr-2017
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