Legal Definitions - criminalist

A criminalist is a forensic scientist who applies scientific principles and laboratory techniques to analyze physical evidence collected during criminal investigations. They work to identify, analyze, and interpret various types of evidence, such as DNA, fingerprints, firearms, trace materials, and controlled substances, to provide objective findings that can be used in legal proceedings. Their expertise helps law enforcement agencies and courts understand the circumstances of a crime.

Here are some examples of how a criminalist's work contributes to criminal investigations:

• DNA Analysis in a Sexual Assault Case: In a case involving a sexual assault, law enforcement collects biological samples from the victim and the crime scene. A criminalist would meticulously analyze these samples in a laboratory to extract DNA profiles. They would then compare these profiles to those of known suspects or against DNA databases to determine if there is a match, providing critical evidence that can link a suspect to the crime.
• Fire Debris Analysis in an Arson Investigation: When a fire is suspected to be arson, investigators collect samples of charred debris from the scene. A criminalist would examine these samples using specialized chemical analysis techniques to detect and identify the presence of ignitable liquids, such as gasoline or kerosene. Their findings can help determine if an accelerant was used to start the fire, supporting an arson charge.
• Trace Evidence and Tool Mark Examination in a Burglary: Following a home burglary where a window was pried open, a criminalist might be tasked with examining the tool marks left on the window frame. They would analyze the unique characteristics of these marks to identify the type of tool used. Additionally, if microscopic fibers were found adhering to the window or a broken object, the criminalist would analyze these trace fibers, comparing them to fibers from a suspect's clothing to establish a potential physical link between the suspect and the crime scene.