Unit 3 AC1.3 Explain how evidence is processed Flashcards
Evidence can be divided into two categories:
- Physical: Also referred to as real evidence, consists of tangible articles such as hairs, fibres, fingerprints and biological material.
- Testimonial: Statements or the spoken work from the defendant, a victim or a witness.
Physical evidence
The concept known as Locard’s Exchange Principle, suggests that every time someone enters and environment, something is added to and removed from it. (‘Every contact leaves a trace’) Scenes of crime officers (SOCOs) always work on the principle that physical evidence has been left behind at every scene.
Testimonial evidence
Testimonial evidence is the spoken word of the witnesses, which could include either the victim or the defendant. Evidence must be admissible, which means complying with the rules of evidence. Statements of witnesses will have been taken by each side and disclosed prior to the court case.
Blood stains
BLOOD STAINS
Can be collected on sterile material if still in liquid form, and left out to dry.
If the blood is already dry, it should be placed in a container and sealed.
Semen stains
SEMEN STAINS
Should be allowed to dry then wrapped in paper and placed in paper bags.
All other relevant pieces of clothing should be packaged separately.
Hair samples
HAIR SAMPLES
Likely to be on clothing and should be wrapped in paper and submitted to the lab.
Small fragments of hair should be placed on paper, marked and sealed.
Fibres and threads
FIBRES AND THREADS
Can be picked up with gloved fingers or tweezers and wrapped in paper, then put in an envelope which is sealed and marked.
Fingerprints
FINGERPRINTS
Can be patent and may be left in liquid such as blood. They can be latent until powder or chemical is used. They should be photographed or on rare occasion, a mould can be made.
Shoeprints photographs
SHOEPRINTS
Photographs should be taken using a tripod for stability, a level and ruler are used to show scale. Casts can be made of impressions then packaged in paper and submitted to the lab.
Bitemarks
BITEMARKS
Should be photographed and a cast can be made.
Casts and photographs of the suspect’s teeth and victim’s teeth must be made for comparison.
Locard’s Exchange Principle
Locard’s Exchange Principle – Refers to Dr Edmond Locard, a French forensic scientist often informally referred to as the ‘Sherlock Holmes of France’. He was a pioneer in forensic science techniques.
Rules of Evidence
Rules of Evidence – Legal rules that explain when evidence, as in a court case, is admissible and when it will be disallowed or rules inadmissible.
Vulnerable witness
Vulnerable Witness – Anyone under the age of 17, or a victim of a sexual offence, or a person whose evidence or ability to give evidence is likely to be diminished by reason of mental disorder, significant intelligence or physical impairment.
Patent
Patent – Clearly visible to the naked eye.
Latent
Latent – Not visible to the naked eye.
