“Contextualising Forensic Science”
Masuma Ahmed-Ali BSc (Hons) MSc PgCLTHE &
Victoria Halliday BSc (Hons) MSc PgCLTHE
Abu Dhabi Police 8th February 2009Translated by: Bashar Sasa
Timetable for the week
Day 1- Contextualising Forensic Science Introduction to the week Define forensic science Importance of Locard’s principle Discuss issues relevant to forensic science
Day 2- Fingerprints and other impression evidence Introduce mark and impression evidence Discuss the different types of mark and
impression evidence Examine the significance of such
evidence
Day 3-Forensic Biology
Provide an overview of forensic biology Discuss the identification of body fluids Discuss the techniques employed in the
production of a DNA profile
Day 4- Laboratory Safety and Management
Principles of laboratory practice Quality Management System for Testing
Laboratories & ISO 17025/2005 requirements
Health and Safety requirements for Testing Laboratories
Day 5- Forensic Toxicology& Plenary Session Define Forensic Analytical Toxicology (FAT) Discuss the relationship of FAT with Clinical
Analytical Toxicology (CAT) and Performance Analytical Toxicology (PAT)
Dose Response Relationship and Therapeutic Index
Specimen Collection and specific examples
Day 1-Learning Outcomes Participants will be able to:
Provide a definition of forensic science Have an insight into the developmental
history of forensic science Understand the variety of disciplines
available in forensic science Appreciate the main principles of forensic
science including Locard’s principle, continuity and contamination
Ice Breaker
Get the person sitting next to you to answer the following questions:
What is your name?What department do you work in?How long have you worked in the
department?
Then tell us…..
What is Forensic Science?
Derived from the Latin word forensis which means “of the forum”
Is the study and application of science to the processes of law
Science + Circumstance
History Mathiew Orfila
Considered Father of Toxicology – published book (1813)
Sir Edward Henry Introduced Fingerprint Bureau to UK (1901)
Edmund Locard Principle of Exchange of Evidence Established First Police Crime Laboratory (1910)
Professor Sir Alec Jeffreys Developed first DNA profiling test (1984) used in a
criminal investigation (1986)
(www.forensicdna.com)
Disciplines in Forensic Science
Common evidence types
Fingerprints Drugs Firearms Toxicology Trace Evidence Tool marks Documents Fire Investigation
Specialisms
Biology Chemistry Odontology Geology Archaeology Entomology Psychology Customs and Excise
The list goes on…….
Forensic Biology
Molecular biology DNA analysis
Botany Plants Fungus Pollen
Bacteria and Viruses Entomology
Forensic Chemistry
Drugs Toxicology Fibre analysis Paint analysis Glass analysis Accelerants Fake goods
Forensic Science in the UK Providers in England and Wales
FSS LGC Forensics Independent Laboratories
Providers in Scotland Laboratories are linked to specific Police
Forces
Forensic Science in the UK Scientific Support
Includes Crime Scene Investigators, Fingerprint Bureau, Photographers
Usually sit in Police Forces Others
Crown Prosecution Service (Procurator Fiscal in Scotland)
Home Office Pathologists/Coroners Office Forensic Medical Examiners
Role of the forensic scientist in the UK
At the crime scene rarely
In the laboratory It depends
In the court room Expert Witness
Locard’s Principle
“every contact leaves a trace”
What is a crime scene?
Crime Scene
Victim Suspect
What is a crime scene?
Location where event took place e.g. Can be a vehicle Inside a building Out in the open air
Can even be the victim
What is Evidence?
Specifically physical evidence Evidence can determine:
whether a crime has been committed what was involved e.g. a vehicle identify who was involved with the crime
Evidence CAN prove a suspect is guilty or show that some or no link is present between the suspect and the crime
Type of Evidence
Type of evidence determines the type of analysis that is carried out
Analysis needs to be relevant to the circumstances surrounding the crime
Collection & Preservation of Evidence Crime scene must be thoroughly documented,
photographed & sketched before any collection of evidence takes place
Physical evidence must be handled & processed in a way that the evidence remains in an unaltered condition, from crime scene to the laboratory- PRESERVATION
Evidence should be submitted intact- blood, fibres, hairs and soil should not be removed unless necessary
Collection & Preservation of Evidence
Compromise of physical evidence Breakage Evaporation Accidental scratching Bending Contamination Loss of evidence
Collection & Preservation of Evidence
Documentation of the evidence Collecting person’s initials Date and time Description of the evidence Location of the evidence Investigating agency & reference/case
number
Collection & Preservation of Evidence Chain of custody
List of persons who came into possession of an item of evidence
Need to know what happened to the evidence from the time of its finding to its presentation in court
May be required to testify in court Authenticity & Integrity of evidence Kept to minimum to avoid confusion
Collection & Preservation of Evidence Equipment used to collect evidence
Forceps, tweezers, scalpels, spoons etc Packaging
Paper containers- packets, envelopes, bags Vials- unbreakable, leak-proof containers
(liquid items) Airtight containers Unbreakable plastic containers (various sizes) Carefully folded paper- “druggist fold/
beechams wrap”
Collection & Preservation of Evidence Collection of Evidence
Fingerprints/palmprints/footprints- photograph before making impression, lifting tape/paper attached to tape
Questioned documents- suitable container. Fibres/hair- small plastic container, folded
paper with sealed edges Broken fingernails- paper packet then in a
paper envelope
Collection & Preservation of Evidence Collection of Evidence
Glass- separate questioned from known. Pack in cotton in sturdy container to prevent further breakage or damage. Label “Fragile”
Firearms- firearm safety! Wrapped in a paper & place in cardboard/wooden box. Ammunition & casings should be packed separately in small cardboard pill boxes
Soil samples- collect samples ASAP from immediate crime scene & areas etc. Plastic vial
Collection & Preservation of Evidence Collection of Evidence
Blood evidence Liquid known samples- leak proof vials. Pack
in cotton/paper. Refridgerate Liquid unknown samples- absorb onto sterile
gauze and let dry Dry stains- plastic vial, keep dry Stained clothing- wrap each article separately.
Place in box to prevent shifting. If wet when found, air dry by hanging
Collection & Preservation of Evidence
Submission of Controls Example 1- blood/ hair from suspect, that can
be compared to crime scene evidence Example 2- buccal swabs from crime scene
personnel Need to take samples of environment
Issues- Contamination
Discredits the integrity of the evidence Should be avoided
How? Robust evidence recovery procedures
E.g. Secure Packaging Rigorous examination procedures in the
laboratory
Issues- Continuity
Chain of custody Documented proof that the integrity of an
item, that may be submitted to the court in future is intact
Analysis of Evidence
Divided into those that are examined In-force externally by a forensic science provider
In-force examinations are generally limited to the analysis of impression marks e.g. fingerprints
Analysis of Evidence
Fingermarks not visible to the naked eye are called latent marks. Can be developed at the scene using
powders May require chemical enhancement (can be
done at the scene, although usually done in a laboratory)
Analysis of Evidence
The type of chemical used may include: Amido black if the fingerprints have been left
deposited in blood Superglue may develop fingermarks on a black bin
bag
Crime Scene marks are passed to the Fingerprint Bureau where they will be compared to suspects or put on IDENT1(national automated fingerprint identification system)
Analysis of Evidence
Other types of Forensic Evidence e.g. blood and hairs are submitted to a forensic
provider.
Crime Scene Investigators (CSI) may perform presumptive tests at the scene however they must then be sent to the forensic science provider for further analysis
Analysis of Evidence
Example Blood Use LMG (Leucomalachite Green) at the
crime scene to test for presence of blood If positive – can swab and send to Forensic
Science provider to obtain DNA profile However can sometimes produce false
positives
Laboratory Practice
Protection (appropriate to the environment)
Personal Protective Equipment (PPE) Face mask Mob cap Lab coat Gloves Foot covers
General personal safety
Staff are responsible for their own safety and the safety of others
Always plan the activity to be carried No eating or drinking Do not apply cosmetics, lick labels, suck
pens, pencils or smoke in the laboratory Cuts/abrasions should be covered Wash hands with disinfectant soap
Laboratory Practice
Anti contamination procedures Wipe down work area with medi-wipes decontaminate all equipment Use disposable consumables Use aseptic techniques
Laboratory Practice
Miscellaneous Monitoring equipment on daily basis Cleaning Health & safety issues Always have a professional attitude Risk Assessments
Individualisation
Depending on the type of evidence can individualise or not Fingermarks individualise as no two people
have been found to have the same fingerprint DNA profiles can only be expressed as a
statistic
Interpretation
Interpretation is the drawing of rational and balanced inferences from observations, test results and measurements
Requires training and experience Need circumstance of crime when
interpreting evidence
Strength Of Evidence
Depends on Evidence type
No support Some support Moderate support Strong/extremely strong support Conclusive
Presentation of Evidence in the UK
Two different forms: Written Statement Can be made in person before the court (if
required)
Presentation of Evidence in the UK
Two main types of criminal court in England and Wales: Magistrates Court Crown Court
Presentation of Evidence in the UK More serious crimes go to Crown Court
Verdict by a jury Judge who determines sentence If found guilty in Crown Court may be given
opportunity to appeal via; Court of Appeal/High Court/House of Lords (not Scotland) (later) Criminal Case Review Board
Expert Evidence
Mainly evidence of opinion rather than fact
Court admits and considers on the basis of the knowledge and experience of the witness
Experts in UK
Council for the Registration of Forensic Practitioners (CRFP)
Forensic Science Society- Professional Body
Any Questions?