Forensics Laboratory
CJUS 201
Criminal Investigation
Part 15
Forensics
1. Called forensics
- pertains to law and courts
- scientific organization to aid the criminal
justice process
- private / government agency
a. Evidence:
- suspect leaves at the crime scene
- suspect takes from crime scene
- anything connected to the crime
Forensics
b. Evidence consists of ‘elements’
- legal requirements
- submitted to a competent court
- by a forensic laboratory
- help uncover the truth
(1) Forensic science
- physical / biological sciences
- examination of physical evidence
(2) Forensic evidence
Forensics
- fingerprints / tool marks / fibers / paints /
etc.
c. Forensic experts
- interpret laboratory analysis
- testify to characteristics of evidence
- biologist / pathologist / chemist / geologist
2. Forensic evidence / judicial process
- submitted to a laboratory
- aid in solving the case
Forensics
a. 3 important roles in the judicial process
(1) Establishes elements
- “suspected” controlled substances
- prove they are illegal
- crime has been committed
(2) Associate / disassociate defendants
- fingerprints
- DNA (hair / body fluids / etc.)
Forensics
(3) Help to reconstruct crime scene
- position of evidence
- movement of suspect / victim
b. Ways lab can assist
(1) Aid in solution by:
- developing MO’s
- proving / disproving an alibi
- connecting / eliminating suspects
- identify property / contraband
Forensics
- verify investigative leads
(2) Prove an element of the crime
- death caused by poison
(3) Identify a suspect or victim
- DNA / prints
(4) Develop associate evidence
- tool mark / tool
Forensics
(5) Test statements / alibis
- paint on fender
- other accident
(6) Reconstruct a crime
- powder burns on victim
- show distance
(7) Corroborate evidence
- match torn cloth to shirt
Forensics
c. Laboratory responsibilities
(1) Inform CJS members of functions
- knowing what lab can do
- provide training to police / prosecutors
(2) Professional testing / examination
- established credentials / expertise
(3) Provide feedback
- copies of lab results sent to agencies
Forensics
(4) Testify in court
- explain process used
- what was found
d. Concepts bearing on quality / usefulness
- all evidence
(1) Mathematical probability
- blood type (O / A / B / AB)
- O = 40% (8 of every 20 people)
- A = 40% (8 of every 20 people)
Forensics
- B = 15%
- AB = 5%
(3 of every 20 people)
(1 of every 20 people)
(2) Class characteristics / similarity
- shoeprint made by Bass Wingtip
(3) Individual characteristic
- individuality of an item
(4) Comparisons
- impression compares to original
Forensics
(5) Rarity
- show uniqueness of evidence
- piece of soil / rare to location
(6) Exchange
- suspect to victim
- victim to suspect
3. Washington State Patrol Crime Laboratory
- RCW 43.43.670
- legislature created crime lab as part of WSP
Forensics
a. Objective / authority
- analyze / scientifically handle
- any physical evidence related to a crime
(1) Provide training / assistance
- local law enforcement personnel
- collection / preservation / packaging
(2) Priority: crimes against person
- overworked / understaffed
- homicides on a daily basis
Forensics
b. State laboratories
- 7 crime labs within state
- 5 full service / 2 limited service
(1) Seattle Crime Lab
- arson examination
- biochemical analysis (serology)
- controlled substances analysis
- DNA analysis / microanalysis (trace)
- forensic chemistry
- forensic documents
Forensics
(2) Spokane Crime Lab
- all Seattle’s except DNA / documents
- firearms examination
- tool mark examination
(3) Tacoma Crime Lab
- same as Spokane
(4) Marysville Crime Lab
- same as Tacoma
- except tool mark / forensic chemistry
Forensics
(5) Vancouver Crime Lab
- same as Tacoma
(6) Longview Crime Lab
- limited in analyzing
- physical evidence
(7) Kennewick Crime Lab
- same as Longview