All crime labs are not created equal. In recent years there has been an exponential growth in the number of crime labs in the United States. These are not like the ones that are seen every week on popular Television shows like “CSI” and “NCIS”. These labs are seriously underfunded and many only offer specialized services (mostly drug testing). A full service crime lab is extremely vital to the processing of crime scene evidence. When a full service lab isn’t available crime scene investigators often have to send materials out of their lab to one that specializes in a particular discipline.
Full Service Crime Lab
There is no definite set of specializations that a crime lab needs to have to be considered “Full Service”, these are simply the ones set forth by Richard Saferstein in his book “Criminalistics”. He reasons that these are the types of units that are found in almost every major metropolitan areas’ criminal labs.
- Physical Science Unit: applies the principles and techniques of chemistry, physics, and geology as a way to identify crime scene evidence.
- Biology Unit: does work on DNA, blood stains, hairs, fibers, and any other biologically relevant materials.
- Firearms Unit: deals with firearms but also examines discharged bullets, casings, and clothing or transitional materials that may contain gunshot residue.
- Document Examination Unit: deals with any and all written materials whether hand written, typed, or printed. This analysis is usually done to prove authenticity but in some cases this unit will check for indented writings on a pad or other writing surface.
- Photography Unit: examines and records all physical evidence using several different photographic techniques: digital imaging, X-ray, infrared, and ultraviolet spectrum are all available.
These are the most common needs of a crime scene investigator.
Crime Lab Specialization
Some crime labs have regional offices that further specialize in any of several disciplines. These regional labs handle offsite requests from other forensic labs that are unable to process and analyze the evidence themselves. Common specializations are:
- Toxicology: looks specifically for drugs or poisons, or the lack there-of, in organs and bodily fluids. This unit is not confined to human specimens, any organism from insect to ape may be tested.
- Latent Fingerprinting: processes and examines evidence for full and partial fingerprints (or other body prints i.e. foot impressions) that were not obtained from the initial crime scene investigation.
- Polygraph: almost exclusively used by investigators and is used mainly in interrogations.
- Computer Forensics: deals exclusively with computers, files, networks, and data transmittal and retrieval. This is the newest type of unit and is growing exponentially to keep up with the needs of law enforcement. The rapid development of new technologies and criminal sophistication has put a strain on these offices.
- Voiceprint Analysis: analysts deal in telephone threats and recorded messages. They may work closely with a computer forensics team and run all voices through a voiceprint analysis program, specifically a sound spectrograph.
What is the Difference Between Crime Scene Investigation and Forensic Science
Each crime scene investigation unit handles the division between field work and lab work differently. Only the portion of the investigation that happens at the actual physical crime scene is a crime scene investigation (and subsequently determined secondary scenes), and what happens in the laboratory is forensic science. Not all crime scene investigators are forensic scientists, some only work in the field - they collect the evidence and then pass it to the forensics lab.
The forensic specialists in the laboratory take the collected evidence and do detailed analysis that cannot be done in the field. Although crime scene investigation and forensic science work together to help prosecutors and law enforcement officers catch criminals their specific job duties are specialized. The crime scene investigator needs to be able to identify potential evidence and potential places that evidence may be found whereas the forensic scientist is charged with determining the specifics of the evidence that is brought into the lab.
Resources
Saferstein, Richard PhD. Criminalistics. 9th Edition. Upper Saddle River, New Jersey; Pearson, Prentice Hall 2007. PP 10-11.
Kenneth Sleight - Ken Sleight is a resident of Haslett, Mi. He was voted among his friends as, "most likely to be the phone a friend on Who Wants to be a ...
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