CSA 1 - Trace Evidence

Trace Evidence

Collects forms of matter (natural/manufactured) that r tiny material/or big lg forms of matter, examples r container gas (bag/metal cylinder), hair, pollen, stains (non-biological), volatile liquids, fibers, paint, glass, soil, and trace evidence can be destroyed/contaminated/transfer so it’s best 2 take precautions

W/o magnification aid, how can trace evidence be collected?

Collect items of evidence w/ trace evidence

Care is used 4 weapon collection unlike what?

Improper handling/packaging that compromises the evidence

Careful photo/document/sketches r critical 4 what?

Optimal use/interpretations/reconstruction of trace evidence

Package item 2 prevent what?

Damage/alteration of evidence; use package 2 mirror item/evidence size/type

Collect_____trace evidence types:

Many

Don’t package what?

Wet/damp evidence

Don’t package_____w/ evidence (pack separately):

Exemplar, standard/reference, ctrl sample

Use bright/alternate light source 2 locate what?

Trace evidence

Collect standard/reference/ctrl sample 4 what?

Lab comparison/exam/elimination 4 multiple analyses if many r collected

Wear powder free gloves 4 what?

Trace evidence collection 2 avoid contamination

Change gloves 2 lower what?

Contamination

Don’t package bodily fluid stained evidence in what?

Plastic bags

Avoid trace evidence alteration unless what?

It is necessary (scrape paint from metal surface)

4 storing evidence use what?

Freezer/fridge dedicated 2 evidence storage 2 guard against biohazard contamination/explosion hazard

Don’t do what type of physical contact?

Cough, sneeze, talk, scratch on collecting/collected sample

4 tweezers/forceps use what?

Pinching source 2 collect item 2 prevent altering/damaging trace evidence

Use adhesive tape 2 lift what?

Evidence in plastic bag b4 contamination prevention of tape roll edges/sides → put unused tape roll portion back in plastic bag when done

Don’t place trace evidence in what?

Manila envelopes (any size), paper envelopes, paper bags

Place trace evidence in what?

In smaller leak-proof container (glassine bindle/canister/teflon lined screw cap glass vial, bottle, jar), or other container

Keep clear acetate sheet protector from what?

Contamination by storing in appropriate size manila envelope/plastic resealable bag

Careful photo/document/sketches r critical 4 what?

Optimal use and evidence interpretation/reconstruction

2 reduce breakage/evidence loss secure what?

Glass container (vials/bottles/jars) in cushioned metal friction lid can w/ lids and cushioned material r balled up paper towels

Use swab 2 collect what?

Trace evidence sample (liquid, powder, gel, forms of matter, evidential/ctrl samples)

2 document trace evidence, ensure object portion w/ stain/trace evidence r photoed/documented/sketches in notes, but the object’s photo must include what?

Scale/ID label, photo w/ + w/o scale, take 1/more photos 2 show object local 4 other object relation in crime scene, show object relation 2 other evidence

2 mark trace evidence, evidence label:

Label container 4 evidence object w/ initials, ID #, date, time, evidence #/locale/description

2 mark trace evidence, evidence #:

Evidence piece has unique # 2 mirror evidence placard/label near evidence/evidence log

2 mark trace evidence, evidence description:

Evidence type (paint, plant stem, glass), OG trace evidence object locale, trace evidence on object

2 mark trace evidence, 4 non-DNA-related stains use what?

“Apparent”/”unknown origin” if stain source not scientifically identified (pillow w/ brown stain of unknown origin on bed’s lower bed sheet)

2 mark trace evidence, label container 2 collect/seal what?

Evidence w/ evidence tape seal 2 protect trace evidence integrity/chain of custody

2 package wet trace evidence, if item is wet determine if_____important/relevant 2 case (acid splash victim), so don’t_____liquid:

Liquid; dry

2 package wet trace evidence, if liquid not relevant, place item on what?

Clean paper piece in secure evidence drying locale (drying rack)

2 package wet trace evidence, if drying rack accessible 2 dry item what step occurs?

Place clean paper piece below evidence 4 drying in drying rack by laying item on/over paper

2 package wet trace evidence (w/o drying rack), lay clean paper piece on what?

Flat surface (table top) in secure locale w/o disturbance/contamination/trace evidence loss by drafts by people walking will be lowered

2 package wet trace evidence (w/o drying rack), place item on/hang over what?

Paper → gently fold paper over object 2 cover it from airborne particles (hair/fibers) that will land on it

2 package wet trace evidence (w/o drying rack), allow item 2 dry naturally w/o what?

Heat/draft exposure (blow dryer)/direct sunlight

2 package wet trace evidence, don’t place 2 items in_____when drying:

Same container

2 package wet trace evidence, what does relevant case liquid pertain 2?

Fire/explosion or in/on object (ignitable liquid carpet) so contact fire investigator/bomb tech/forensic fire debris/explosive analyst, or it may be involved in injury/damage 2 person/property/object

2 package wet trace evidence, small sample 4 relevant case liquid:

Secure appropriate sized glass container w/ Teflon-line screw cap lid/air-right non-reactive lid

2 package wet trace evidence, lg sample 4 relevant case liquid:

Document wet area locale w/ photos, notes, sketch → cut/remove wet area 2 treat as small sample, then soak object/liquid drops on surface (non-porous surface) → use gloved hands → squeeze liquid drops on glass container/use swab 2 collect drop samples, form lg liquid drop/pool 2 transfer w/ pasteur/plastic transfer pipette in glass vial

2 package wet trace evidence, consider appropriate what?

Hazardous label

2 package dry trace evidence, 4 dried object_____paper on/over dried object then contain_____fallen on paper:

Pick up/fold; trace evidence

2 package dry trace evidence, _____folded paper 2 indicate_____:

Label; dried item’s evidence # (paper used below evidence #36 while drying)

2 package dry trace evidence, repackage item w/ what?

OG paper/container

2 package dry trace evidence (w/o container), save OG packaging 4 what?

Evidence instead 2 repackage

2 package dry trace evidence (w/o container), put labeled OG package in what?

New container w/ evidence 2 collect

2 package dry trace evidence (w/o container), label container w/ what?

Evidence # 4 item (OG package 4 evidence #36)

2 package dry trace evidence, place glass vials/bottles/jars in what?

Cushioned metal friction lid container 2 reduce breakage

2 package dry trace evidence, 2 reduce breakage/evidence loss secure glass container (vials, bottles, jars) in what?

Cushioned metal friction lid can w/ lids/cushioned material (balled-up paper towels)

2 package dry trace evidence, don’t put trace evidence in_____w/o placing evidence in smaller_____:

Manila envelopes (any size), paper envelopes/bags; glassine/paper bindle, leak-proof container, Teflon lined screw cap glass vial, bottle, jar

2 package dry trace evidence, keep clear acetate sheet protector free from what?

Contamination by storing in manila envelope/plastic resealable bag

2 package dry trace evidence, tape lifts r placed on what?

Clean/clear (no translucent) acetate sheet protector then place sheet protector in manila envelope

Ctrl sample

One known by collector w/o evidence 2 represent matrix material on where evidence rests (wallboard/carpet piece)

Compare sample

Has evidence w/o collector’s knowledge (fire debris) and represents matrix material on evidence/made of same evidence matrix material (glass fragments from broken window)

What is compared w/ the evidential sample?

Ctrl sample

4 ctrl/compare samples 4 trace evidence, what is the 2nd container labeled as?

Ctrl sample (initials, ID #, date, time, evidence #, ctrl sample locale in relation 2 OG sample, ctrl sample description)

4 ctrl/compare samples 4 trace evidence, identify sample as what?

Ctrl/compare sample (write words in bold print on container)

Ctrl sample #:

Evidence piece/ctrl has unique #/letter # added 2 OG evidence 2 denote ctrl sample (if OG evidence # = #32; ctrl sample = #32A/32.1)

Ctrl sample description:

Sample/matrix material type (wallboard), material locale, sample locale in relation 2 evidence sample

Ctrl sample collection:

Use tool, cut out, collect/remove same matrix material portion on evidence sample or part of said sample (paint smear evidence on paint), locate same area material from OG trace evidence sample taken but w/o evidence present (undamaged paint area)

4 ctrl/compare samples 4 trace evidence, how r the samples normally received?

Cut out/collect/scrape ctrl/compare sample w/ scalpel/utility knife/wallboard saw/carpet knife/single edge razor blade, use clean blade only (never one used 2 cut evidential/ctrl sample prior 2 w/o changing/cleaning), if many layers (carpet/carpet pad/multi-layer paint) of material r observed/collected in OG sample 2 collect all multiple layers 4 ctrl/compare sample

4 ctrl/compare samples 4 trace evidence, how is a liquid sample collected?

Glass/plastic transfer pipette → place in glass Teflon lined screw cap vial/bottle of small size 4 sample, use swab 2 collect liquid trace evidence sample (evidential/ctrl) is last resort → put swab in screw cap/vial/air-tight container