Year 10 Forensic Science

What is Forensic Science?Hazards and ProtectionCollecting Evidence

Learning intention/goals

To understand what Forensic Science isTo understand the roles of Forensic ScientistsTo understand the hazards and risks associated with Forensic ScienceTo become familiar with the integrity of collecting evidence

Success criteria

I understand what Forensic Science isI understand the roles of Forensic ScientistsI understand the hazards and risks associated with Forensic ScienceI am familiar with the integrity of collecting evidence

WHAT IS FORENSIC SCIENCE?

•the application of a science to answer questions of interest to a crime.

•comes from the Latin forensis, meaning "of or before the forum."

•In Roman times, a criminal charge would be presented before the public in the forum. Both the person accused and the accuser would give speeches. The individual with the best argument would determine the outcome of the case

•aka “The French Sherlock Holmes”

•formulated the basic principles of forensic science

•“Every contact leaves a trace”

•Started the first police laboratory in Lyon in 1910

Edmond Locard (1877 – 1966)

Research ~ HazardsIn pairs or using your BYOD, complete the following. You have 2 mins

on the timer

1. What do these initials mean:• HSE• PPE• COSHH2. Complete the following:– A hazard is – A risk is

3. What is meant by sharps?

Health and Safety Executive

Personal Protection equipment

Control of Substances Hazardous to Health

Anything that might cause harm. The chance that someone could be harmed.

Any sharp instrument or object.

Method of entry into the

body

inhalation

skin absorption

ingestion

injection

Nature of hazard

contaminants that make contact with

the skin

contaminants such as sharp objects that

can puncture the skin

airborne e.g. dusts, smoke, vapours,

gases

contaminants that are able to enter the

mouth

Action to reduce the risk

wash hands before eating or smoking. Do not bring food into

unsuitable areas.

Use equipment such as safety glasses, gloves and other protective

clothing

Exercise caution when handling. Wear gloves at all times. Dispose

of sharp objects in special containers.

Ventilation and/or respiratory protection masks.

Protective clothing

Face maskProtects against inhaled particles and prevents

contamination from the officer’s saliva.

GogglesProtect eyes from chemical hazards.

Hooded Plastic SuitProtects the officer at

the scene and prevents contamination of the

scene.

GlovesProtect from materials absorbed through the

skin, prevents contamination by

fingerprints and DNA.

Shoe coversPrevent footprints

from damaging evidence.

Complete the task in your booklet on protective clothing.

RolesDetective (D)

Senior Investigating Officer (SIO)

Scenes of Crime Officer (SOCO)

Senior Scenes of Crime Officer (SSOCO)

Scene Guard

To question suspects and investigate lines of enquiries.

To co-ordinate the overall investigation

To record and recover valid evidence at crime scene .

To manage the forensic examination of the scene.

(SG) To preserve the scene and to make sure no unauthorised persons enter the scene.

Risk Assessment

What hazards might be present here?

What could you do ensure risk is minimised?

Processing a Crime SceneValid Evidence

Valid evidence is based on the truth. It can be accepted in court.Forensic scientists use two procedures to make sure evidence is valid:

• Avoid contamination

•Record accurately

ContaminationDefinition: The unwanted transfer of material which must be avoidedat a crime scene

Individuals can contaminate the scene or evidence at any time by:

• Leaving fingerprints / hairs / fibres / DNA• Not sealing the evidence properly• Putting more than one piece of evidence in a bag at once• Using old equipment

Contaminated evidence can not be used in a court of law and may result in criminals being set free.

Establishing EvidenceYou will need to find out: • How contamination of the crime scene is prevented • How the officers protect themselves from harm• What photos and measurement were taken• What evidence is collected, and how it is stored.• What can be learned from the evidence? Protecting the evidence at the Crime scene Look at the next slides and determine the measures thathave been put in place to protect the validity of theevidence.

Picture A ~ Cars

Tape used to created a cordoned off area to prevent people from entering

the scene unauthorised.

Police officers used to prevent unauthorised people entering the area.

Picture B ~ Scene of Crime Officer (SOCO) at work

TentProvides screen and

distinct barrier

SuitsSOCOs gathering

evidence correctly dressed. NB. Any Police Detective entering the

scene would be required to wear a protective suit.

BUT they don’t on

TV do they?

Stepping PlatesProvide a safe and

secure way of approaching the

scene.

Picture C ~ On the ground and aroundTent

Provides screen and distinct barrier

Crime Scene TapeCreates an inner

cordon.

Full protective clothing!

Evidence markers.

Processing a Crime SceneCorrect processing of a crime scene is essential to gather as much

information as possible and prevent contamination.

STEP 1INTERVIEW - The SOCO arrives on the scene and makes sure it is secure.

An initial walk-through is conducted to get a feel for the crime scene.

The first officer at the scene and/or the victim is interviewed to ascertain the "theory" of the case; what allegedly happened, what crime took place, how was the crime committed etc. This information may not be 100% factual but it will give the SOCO a place to start from.

The SOCO also needs to find out if anything has been moved. Potential evidence is noted but at this point, nothing is touched.

Processing a Crime SceneSTEP 2DOCUMENTATION – Is the "theory" of the case supported by what the

SOCO observes? Examine the scene to identify evidence, point of entry and exit, the general layout, etc.

The SOCO thoroughly documents the scene as well as any potential evidence by taking photographs and drawing sketches during a second walk-through. Sometimes, a video walk-through may be conducted. Again, nothing is touched.

Processing a Crime SceneSTEP 3

PROCESSING - Now it's time to touch stuff -- very, very carefully. The SOCO systematically collects all potential evidence, tagging it, logging it and packaging it so it remains intact for further analysis by a crime laboratory.

The lab processes all of the evidence collected at the crime scene. When the lab results are in, they go to the lead detective on the case.

It is essential that any items of physical evidence can be traced from the:

crime scene → lab → lab report → courtroom

This is known as maintaining the chain of custody or continuity of evidence. If the chain is broken, the forensic investigation may be fatally compromised.

Processing a Crime Scene

Search PatternsThere are several search patterns available for a SOCO to

choose from to assure complete coverage and the most efficient use of resources.

Search Patterns

1) Inner SpiralThe SOCO starts at the perimeter

of the scene and works toward the centre.

2) Outer SpiralThe SOCO starts at the centre of scene (or at the body) and

works outward.

Spiral patterns are good if there is only one SOCO at the scene.

Search Patterns

3) ParallelThe SOCO team form a line and

walk in a straight line, at the same speed, from one end of crime

scene to the other.

4) GridTwo parallel searches, offset by

90 degrees, performed one after the other.

Search Patterns

5) ZoneThe lead SOCO divides the crime scene into sectors,

and each team member takes one sector. Team members may then switch sectors and search again

to ensure complete coverage.

TASK

Read the Allison Bayden –Clay murder case and decide which search patterns were employed to gather evidence and why.

• Quadrant search (Zone)• Link Method • Strip or line search (Parallel)• Grid• Spiral Search (inner and outer)

You will need to include a diagram of the SOCOs pathway through the crime scene.

Also include any advantages and disadvantages of the search patterns.

In your opinion, which would be the most ideal search pattern?

Trace evidence (gunshot residue, paint residue, broken glass, unknown chemicals, drugs, poison)

Impressions (fingerprints, footprints, tool marks)

Body fluids (blood, semen, saliva, vomit)

Hair and fibres

Soil and insects

Weapons and firearms evidence (knives, guns, bullet holes, cartridge casings)

Documents (diaries, suicide note, phone books; also includes electronic documents like answering machines, text messages)

In General:- What kind of evidence might a SOCO be searching for?

Video: Forensic Science used to solve real crime scenes

• https://www.youtube.com/watch?v=1B6oOOlGT2M&list=PL89QP7ZwONKmVLlYwPyf6aI-wIrQjbnqX

Review: In your Booklets

• Name 3 different occupations related to Forensic Science and briefly describe their role ..........................................................

• Valid evidence is dependent upon two things. Name them ............

• Forensic Science is the ..............................