The main purpose of Police Department Forensic Services Unit is the application of modern sciences to the investigation of criminal cases. Investigators are primarily tasked with the retrieval, preservation, documentation, and processing of physical evidence present at crime scenes. Investigators also perform a number of laboratory functions as well.
Forensic science is the application of science to criminal and civil laws, mainly—on the criminal side during criminal investigations, as governed by the legal standards of admissible evidences and criminal procedure.
Forensic scientists collect, preserve, and analyze scientific evidence during the course of an investigation. While some forensic scientists travel to the scene of the crime to collect the evidence themselves, others occupy a laboratory role, performing analysis on objects brought to them by other individuals.
In addition to their laboratory role, forensic scientists testify as expert witness, both criminal and civil cases and can work for either the prosecutions or the defense.