Forensics Flashcards
- establish rapport wih witness
make witness more comfortable, providing more info, learn ab communicaition style
- Inquire about witness condition
simple how are u can show if there mental conditions
- use open ended questions
avoid yes or no questions, use direct questions
- clarify info received from witness
check what they said, make asure recorded right
- document info obtained from witness
get their contact info and identity, nessescary for follow up interview
- enourage witness to contact after
if any additional info is remebered tell the witness to contact after, no matter how small it is important
- encourage witness to avoid media contact
contiminates witness memory, can encourage fabrication, bias
- instruct witness to avoid discussing details w other witnesses
can be influenced by info, important to compare info w other witnesses, always keep witnesses seperate
Bloodstain pattern analysis (BPA)
may clearly define the location of the victim or assailant by establish both their actions. Eg What weapons caused these bloodstains? how many times struck?where was victim?
What are the 3 ways speed and distance of impact spatter help
Low velocity spatter, 10 cm per second happends from a wound
medium velocity spatter, 10-50 cm, typically from a beating/stabbing
High velocity spatter, more than 200cm per second, indicate gunshot wounds typically
General rule?
smaller the blood drop, greater the force it took to create it
2 main patterns of gunshot wounds
forward spatter - blood travels same direction as bullet, exit wounds
back spatter - opposite, blood is forecully projected from entrance wound
When does blood usually clot
3-6 mins after shed
How are fingerprints used
since they are unique forms of identity and no 2 people have the same fingerprint, its used for security, identification, etc
what are finger prints made of
unique patterns made from friction ridges (raised) and furrows (recessed)
limitations of prints
must be a known print to compare, no way to tell time, eg murder in kitchen, ur prints are reasonably there
Why are documents reviewed?
usually whire-collard crimes, for evidence of alterations, obliterations and page substitutions
what acts as a revealing clue
ink, paper, ribbon, writing tools, etc used in production may
3 main principales of comparing handwriting
- no 2 skilled writers exhibit identical writing features
- every person has a natural range of variation to their handwriting
3.no writer can exceed their skill level
frauduent checks
common example, can tell differences by ink and lettering differences
3 steps of how its done
- collecting known and unknown (req, controlled)
2.How and where analysis is performed (lab w mircoscopes) - Examination of handwriting’
(comparisons, cursive to cursive etc)
Requested and collected specimens
requested writing specimens: speciments created under carefully controlled condiotions
Collected specimens: completed by subject prior to inves
Limitations of handwriting?
Insufficient quantity, quality, known specimens before
distortion/disguised writing
what is ycja?
youth criminal justice act, explains how ppl age 12-17 will be treated if they break the law
