In many criminal investigations, it is necessary to determine and prove through various types of physical evidence, that a particular person was present at the scene of a crime. For this reason the collection and forensic examination of evidence, such as fingerprints, blood, hair, fibers, soil, and glass is routinely practiced. Since the criminal must either be walking or driving as they enter or leave a crime scene, often it is important that shoe and tire impressions are collected, as such can often provide excellent physical evidence.
The Evidence Collection Unit (ECU) is charged with the processing of crime scenes and for providing expert court testimony. The ECU photographs, collects, and examines evidence discovered, and collected at crime scenes. ECU Officers are trained to photograph, prepare, and collect footprint, tool, and tire impressions.
The ECU tracks, maintains custody, and disposes of items found, confiscated, forfeited or held as evidence. It is responsible for auctioning unclaimed property, and for the destruction of drugs and weapons.
As noted below from the FBI’s bulletin report, crime scene processing and proper evidence collection is crucial to the successful investigation and prosecution of crimes.
“Crime scene examination is a forensic science activity that helps investigators identify, interpret, and recover physical evidence from a crime scene so that the evidence can be physically analyzed by the investigator or forwarded to the appropriate scientific discipline for further scientific analysis. The investigator is also responsible for the management of the crime scene, any attending scientific specialists, and the case management of evidence. In order to undertake this responsibility, the investigator must have the competence to record the crime scenes, as required, by notes, diagrams, photography, and video. The collection procedures must be of the highest level in order to provide integrity of exhibits and prevent any cross-contamination, particularly with trace evidence.”
The Property and Evidence Section is an essential part of the department. The effective investigation and prosecution of an offender relies on information obtained through careful, methodical, and proper use of evidence. Presentation techniques and proper safeguards require strict control in respect to handling, processing, security, and disposition of evidence.