Finger printing

• Identify the different ways which evidence can be analysed from a crime scene.

• Explain how to analyse evidence taken from a crime scene.

• Be able to solve a crime by analysing crime scene evidence.

Learning Objectives

What pieces of evidence could you

collect from the crime scene?

Bellwork

There are many different ways of collecting

evidence from a crime scene:

•Blood samples•Finger printing•Hair and fibre samples•Entomology – insects•DNA•Trace evidence – very small amounts

Look at the information sheets given to you. How would you carry out each of these tests?

Complete the table to achieve 13P3

New Information

Type of TestType of evidence

(biological, chemical, physical)

Why carry out this test?

Blood Samples

Biological

Evidence from insects can help an investigator find the time of death and any change in its location. Expected life cycles and development times can help estimate

time of death.

13P3Part 1

Type of TestType of evidence

(biological, chemical, physical)

Why carry out this test?

Blood Samples Chemical Different blood groups are identified by looking at substances found in the blood.

DNA Biological DNA is unique in every individual (apart from identical twins) and therefore can identify the victim or suspect in a case.

Finger printing Biological/Physical Fingerprints stay the same throughout your life and are unique in individuals and

therefore can identify a person was at the scene of a crime.

Entomology Biological/Physical Evidence from insects can help an investigator find the time of death and any change in its location. Expected life cycles and development times can help estimate

time of death.Hair and fibre

samplesPhysical If hair is pulled from the root there will be

DNA which can be collected. Hair can place people in contact with a victim.

Trace evidence Physical Is present in small quantities but may be missing links and clues in investigations.

Things such as glass, paint, fibres or traces of saliva.

For each of the different types of the evidence that you could collect, match up the sample type to its description.

Complete the sheet to achieve 13P3

Activity13P3Part 2

• Record your fingerprints in the grid

• Can you see any patterns?– Describe the shapes you can see

underneath your prints.

Classifying Fingerprints

• There are three main fingerprint types• Which types did you find?Arch Whorl Loop

Fingerprints

CSI – Demonstrate• At 3am this morning residents of Cramlington were

awoken by the sound of a gunshot. • When police officers arrived at the scene they found

the body of Christina Green.

• A gun was found in a residents garden, a partial fingerprint was found. We have 4 suspects, and their fingerprints.

• It is your job to match up the partial fingerprint to the full fingerprint by looking at the different features of the fingerprints.

Demonstrate - CSI

Suspect 3 Suspect 4

Suspect 1 Suspect 2

Who Dunnit?

Evidence (partial finger print)

Using the partial finger print collected at the scene of the crime, work out who was at the scene of the crime.

What features can you pick out?

As part of your training programme you need to produce a poster of how you will analyse the collected evidence. Identify the evidence that has been collected, and indicate whether each piece of evidence is either; biological, chemical or physical. You must include a flow diagram which explains how to collect this data without contamination. Use this information to produce your poster.

Include:A plan which will detail how you carry out the practical safely

include:•The type of evidence (finger print)

•The procedure you will use•The equipment you will need

•The observations you will look for•How will you record your result?

Also include:1. The 6 types of evidence and why they are used.2. The process of analysing finger prints – what do you look for and why?3. What are the negative points about finger print evidence?

Coursework – 13P3 Part 3

1. What are the three different finger print shapes called?

2. How do you collect a finger print without contaminating the evidence?

3. Name three different types of evidence you could collect from a crime scene.

4. Why is DNA evidence such a strong piece of evidence to have?

Review

As part of the training programme, forensic scientists have to make notes about how to record observations and measurements during investigations. You must produce a log which clearly states how to record these observations and specify how long each observation will take.

Include:

1. The 6 types of evidence and why they are used.

2. The process of analysing finger prints – what do you look for and why?

3. What are the negative points about finger print evidence?

Coursework – 13M2

As a senior forensic scientist you should complete risk assessment sheets for the analysis of all the evidence you have collected as good practice. Make sure you consider the risks from the evidence itself, any chemicals or materials used and techniques or processes.

Include:

1. The 6 types of evidence and why they are used.

2. The process of analysing finger prints – what do you look for and why?

3. What are the negative points about finger print evidence?

Coursework – 13D2