Lecture 2 - CSI and Physical Evidence Considerations Flashcards
Most crime labs suffer from too much evidence. Too much clothing, too many cigarette butts, too much glass, COVID masks, etc.
ALS doesn’t detect everything
Samples can be present in really small quantities. Also, other bodily fluids show up under luminol that may not be relevant to the investigation. And it can’t be distinguished from blood, etc.
Two big decisions with evidence
Deciding what gets collected - CSIs and law enforcement
Deciding what gets sent to and analyzed by the lab. - Law enforcement, DA, forensic lab, defense attorney, others. Crime Lab Directors, those facing pressure
Cases where the crime lab can push back:
couch example: Touch DNA is low quality
Too many people have been on that couch
You’d need to submit a whole couch
Other contaminants
Fibers complicate process
Lab could push back. However, this involves a minor and assault. High-profile. So the lab will run it. Same with homicide.
Anthrax Example
There is a huge push for techniques that can pre-screen DNA. Because most DNA collected gives nothing. Determine which ones have DNA, etc. before testing.
Instead of DNA extraction first. ALS? Immunoassay? SNPs? Cell charac? Fluorescence?
DNA profiling is a two to three day process. 1000 dollars/sample. His opinion: publicly funded crime labs, backlog is mostly due to time, not always money.
Once identified, physical evidence is packed and stored carefully. PPE is used to avoid contamination.
Two big enemies with DNA
heat, moisture (water). Water is bigger than heat. Needs to be properly vented if wet.
Forensic Labs all over the country have diff capabilities - depending on equipment/facilities, funding, staff, expertise.
Public Crime
City/County
Regional
State
Federal
Private Commercial
Toxicology
DNA/ Serology
Firearms/Toolmarks
University Labs (ad hoc analyses)
-Special Circumstances
Anthropology
* Toxicology
* Chemical profiling (e.g., isotopes)
Forensic Laboratories
Criminalistics
- basic
- expanded
specialized services
Basic Crime Lab Services (Publicly Funded)
Physical Science/Trace Unit
Biological Unit
Firearms/Tool Marks
Photography Unit
Fingerprint Unit
Well equipped/Private
Toxicology
Drugs, alcohol, poisons
Polygraph
Lie detector analysis
Digital Forensics
Cell phone, computer analysis
Genetic Genealogy (IGG) - 5-10 years was just two women doing pro-bono work.
This can change over time due to case loads, pressure.
Because of the rise in cannabis, other drugs, toxicology can be expanded.
Specialized Services
Forensic Anthropology
Forensic Entomology
Forensic Psychiatry
Forensic Odontology
They are specialists, they have day jobs. They are not hired regularly by crime labs, only for consultations.
They need specialized animal forensic services. Human crime labs cannot deal with animal DNA.
Bioterrorism, chemical terrorism
most dealt with by FBI, DHS NDACC Lab - shift since 9/11
Explosive Devices
(TDACC, ATF, FBI)
Micro-Lecture: Careers to FRSC!
Think beyond government labs!
Biggest areas of job growth + availability are often contracting labs.
FBI Labs, State Labs have huge backlog = contract with outside labs to process samples.
Outside labs = bode, sorenson, I^3, MRI Global, Signature Sciences, Battelle.
Huge growth in companies,
indeed /monster/USA.gov = don’t look at them
FBI and other federal agencies are often required to look at USA.gov but don’t look at them. Jobs aren’t active.
Instead, LinkedIn, Individual websites for companies (shows you are engaged/interested), agencies, Placement services, headhunters.
