Trace evidence in criminal investigations

Criminal Justice

Trace Evidence

The objectives of a crime scene investigation include locating and preserving evidence the criminal leaves behind, because most crime scene personnel know that no crime goes without some kind of evidence left behind, Locard's principle says a contact must always leave a trace somewhere. That trace can include anything from blood and hairs to fibers and paint chips, and all can be useful to the crime scene investigator. Personnel investigating the crime scene can include detectives, officers, forensic scientists, and even arson investigators.

The personnel at a crime scene have one major purpose, to locate and preserve as much evidence as possible to reconstruct the crime and locate the perpetrator. Whether the crime is a vehicle accident, a murder, or an arson, they must locate the physical evidence that ties the perpetrator to the crime, and have the ability to spot the evidence and preserve it so it can be used effectively in court when the perpetrator is located and tried. That means they have to know how to locate evidence that can be traced, but they also need to know how to test it and preserve it so it can be used at a later date. They have to guard against contamination, and make sure they collect enough evidence to tie it to a perpetrator.