Criminology unit 3 ac1.3
What are the two types of evidence? - correct answer-Physical and testimonial
What is Locard's exchange principle? - correct answer-Every contact leaves a trace
• Every time someone enters an environment,
something is added and something is removed
• Crime Scene Investigators always work on the principle that physical evidence is left behind
at every scene
What is the CJA label? - correct answer-The Criminal Justice Act (CJA) sets out the
information required to be submitted with a piece of evidence.
• There a 5 essential pieces of information to be included and without these the evidence will
be inadmissible in court
• This could effect the use of this evidence
• The reverse of the label contains a log which keeps a record of who has had the evidence
and where it has been. This is known as continuity
Blood Evidence - correct answer-COLLECTION - As shown on previous slides, either whole
item, swab, scrape (dry) or pipette (liquid)
• TRANSFER - blood is collected in a vial or plastic tube, which is sealed and put into an
evidence bag.
Must always contain CJA information on the bag or with CJA label attached. Bags are sealed
for
transportation (tamper proof seal)
• STORAGE unless dry, the blood is stored in a freezer to protect it from degrading
• ANALYSIS blood will be analysed to obtain DNA info, blood group. Will determine if it from
the victim
or offender
• PERSONNEL INVOLVED DNA specialist
• POSSIBLE PROBLEMS evidence degrading if not stored properly, inadmissible if CJA info
not
completed, can lose integrity if the scene is not secured at the beginning
• CASE STUDIES - Sadie Hartley
Saliva Evidence - correct answer-COLLECTION - As shown on previous slides, whole item
plus swabs on drinks containers and bottles.
• TRANSFER - retrievable items in rigid containers to prevent damage and then placed in an
evidence
bag. Swabssameaswithblood,swabtubessealedandplacedinevidencebag.Mustalwayscontain
CJA information on the bag or with CJA label attached. Bags are sealed for transportation
(tamper proof seal)
• STORAGE unless wet, the items can be stored in a cool dry place (freeze if wet)
• ANALYSIS saliva will be analysed to obtain DNA info.
• PERSONNEL INVOLVED DNA specialist
What are the two types of evidence? - correct answer-Physical and testimonial
What is Locard's exchange principle? - correct answer-Every contact leaves a trace
• Every time someone enters an environment,
something is added and something is removed
• Crime Scene Investigators always work on the principle that physical evidence is left behind
at every scene
What is the CJA label? - correct answer-The Criminal Justice Act (CJA) sets out the
information required to be submitted with a piece of evidence.
• There a 5 essential pieces of information to be included and without these the evidence will
be inadmissible in court
• This could effect the use of this evidence
• The reverse of the label contains a log which keeps a record of who has had the evidence
and where it has been. This is known as continuity
Blood Evidence - correct answer-COLLECTION - As shown on previous slides, either whole
item, swab, scrape (dry) or pipette (liquid)
• TRANSFER - blood is collected in a vial or plastic tube, which is sealed and put into an
evidence bag.
Must always contain CJA information on the bag or with CJA label attached. Bags are sealed
for
transportation (tamper proof seal)
• STORAGE unless dry, the blood is stored in a freezer to protect it from degrading
• ANALYSIS blood will be analysed to obtain DNA info, blood group. Will determine if it from
the victim
or offender
• PERSONNEL INVOLVED DNA specialist
• POSSIBLE PROBLEMS evidence degrading if not stored properly, inadmissible if CJA info
not
completed, can lose integrity if the scene is not secured at the beginning
• CASE STUDIES - Sadie Hartley
Saliva Evidence - correct answer-COLLECTION - As shown on previous slides, whole item
plus swabs on drinks containers and bottles.
• TRANSFER - retrievable items in rigid containers to prevent damage and then placed in an
evidence
bag. Swabssameaswithblood,swabtubessealedandplacedinevidencebag.Mustalwayscontain
CJA information on the bag or with CJA label attached. Bags are sealed for transportation
(tamper proof seal)
• STORAGE unless wet, the items can be stored in a cool dry place (freeze if wet)
• ANALYSIS saliva will be analysed to obtain DNA info.
• PERSONNEL INVOLVED DNA specialist
