The Saint John Police Forensic Identification Unit (FIS) is responsible for the collection, preservation, and analysis of evidence in criminal investigations. FIS is composed of highly trained specialists who examine crime scenes, collect physical evidence, and use advanced scientific techniques to analyze and identify evidence.

The unit is also responsible for creating a detailed report of all evidence collected and for maintaining a secure chain of custody for the evidence. FIS is essential in providing the Saint John Police with the necessary evidence needed to investigate and to present the case in court.