L5: Forensic Strategies, evidence recovery song evidential value

Question 1

what was the Rolex murder?

Answer 1

Husband and wife attacked outside their house.
steal two rolexes.
wife shot and died.
husband hit their car

Question 2

what evidence was there?

Answer 2

fragments of getaway car found on husbands car( glass and paint)
bag of clothes from ones ex girlfriend

Question 3

who was arrested for the Rolex case?

Answer 3

Jason James and Daniel Whyte - life imprisment

Question 4

what evidence did the duffle coat provide?

Answer 4

gun shot residue and DNA profile of Jason James

Question 5

in a burglary what evidence could there be?

Answer 5

finger marks around entrance 
tool mark son door 
fibres on door 
shoe marks 
hai or fibres

Question 6

how do you priorities evidence?

Answer 6

evidential value
nature of crime
cost-effectiveness

Question 7

what evidence is prioritised?

Answer 7

finger marks - cheap high value
blood - DNA
shoe marks - cheap fairly useful

Question 8

whats a volume crime?

Answer 8

opportunity theft, criminal damage

Question 9

whats a major crime?

Answer 9

unexplained death, rape, missing child

Question 10

what is evidence retrieval and subsequent examination determined by?

Answer 10

Cost-effectiveness for various evidence types
o Forensic work in-house by police is cheaper than bought-in analyses
o Need to provide early leads to the investigation (investigative forensics) o Need to identify (and exclude) individuals
o Need to provide strong evidence in support of a prosecution in court

Question 11

what are the critical areas to collect evidence from?

Answer 11

Those likely to yield most evidence

Those that will allow further examination to progress

Question 12

what is a control?

Answer 12

control is a standard material that may be needed in an analysis to ensure that it does not interfere with the analysis of the evidential material itself.

Question 13

what is a reference?

Answer 13

reference is a sample of material that is similar or may be identical to the evidential material where it is intended that this sample be subjected to a comparative analysis with the evidence itself.

Question 14

How are finger prints recovered?

Answer 14

• non pourras surface is dusted with powder and lifted
• paper taken to lab
• photograph if in blood

Question 15

How are shoe marks recovered?

Answer 15

• Photographed, enhanced, lifted at the scene
• Marks in dust – electrostatically lifted
• Marks in soft ground – lifted using a casting material to give a 3D profile

Question 16

How are tool marks recovered?

Answer 16

• Where the action of a tool deforms the surface
• Photographed at the scene
• Remove item/ surface to laboratory or
• Used a plastic casting compound to get a 3D profile of the mark

Question 17

what are the 3 types ofDNA samples?

Answer 17

o Where the action of a tool deforms the surface
o Photographed at the scene
o Remove item/ surface to laboratory or
o Used a plastic casting compound to get a 3D profile of the mark

Question 18

what are sources of DNA evidence ?

Answer 18

blood traces, semen, vaginal fluid, sweat and urine, saliva

Question 19

are blood traces a good source of DNA?

Answer 19

excellent, stain drys naturally

Question 20

are semen traces a good source of DNA?

Answer 20

excellent, aspermia or sperm depleted semen possible profile from cells shed during ejaculation

Question 21

Is vaginal fluid a good source of DNA?

Answer 21

ok due to lining cells, may be in present semen

Question 22

are sweat and urine a good source of the DNA?

Answer 22

not useful unless cells present

Question 23

are saliva a good source of DNA?

Answer 23

DNA from buccal cells from mouth

cells not from the liquid saliva

Question 24

Is hair a good source of DNA?

Answer 24

• Pulled hairs are OK for STR profiling

- Shed hairs or hair shaft are not suitable for STR but may be use for mitochondrial DNA analysis

Question 25

is faeces a good source of DNA?

Answer 25

Only mitochondrial DNA obtainable

Question 26

is Dandruff, surface skin cells a good source of DNA?

Answer 26

Only low copy number (LCN) DNA

analysis possible

Question 27

are fingernail clippings a source of DNA?

Answer 27

Preferable to scrapings

OK for STR profiling only if blood present

Question 28

How to preserve DNA?

Answer 28

Scrape or cut dried material
Do not touch pulled hair roots
Avoid storage in warm, moist conditions o Freeze swabs as soon as possible
Air-dry wet materials
Polythene bags ONLY for dried material

Question 29

How to recover fibres?

Answer 29

o Tape-lift, mount on acetate sheet , packaged in poly bag or envelope and taped at all seams and openings.
o Ensure exact location of lift is documented on the label
o For control samples (e.g. Carpets, upholstery), submit more than just tape-lifts; tape-lift exhaustively

Question 30

How to recover fibres?

Answer 30

tape lift
mount on acetate sheet
envelope
tape envelope
label where lift happened

Question 31

How to recover hair?

Answer 31

control hair pulled by root
head 25
pubes 10

Question 32

How to recover glass?

Answer 32

collect 6 pieces from broken area
not floor unless necessary
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