Forensic Identification Unit
The Vancouver Police Department's Forensic Identification Unit (FIU) has an authorized strength of 23 sworn police officers (one constable position is dedicated as a training officer) and two sergeants. Two civilian photolab technicians and one office assistant provide additional support for the Unit.
The Unit's major role is to apply forensic sciences to collecting evidence that will be admissible in court. Although most of FIU's work involves major crimes, the squad assists all VPD investigators with gathering forensic evidence.
The Science & Skills of Forensics
The Theory of Transfer states that when two surfaces come into contact, a transfer of material or an impression from one to the other usually takes place. The basic job of a FIU investigator is to identify the evidence that is left behind by this transfer, to collect this evidence, to preserve it and after analysis, present the results in court. This requires extensive training in many of the forensic sciences.
Working with human remains is never pleasant but is a necessary skill that FIU members are trained in. Careful collection of evidence at the discovery site can reveal a wealth of information. Although Anthropology is often the name given to this activity, a number of sciences are employed. The skills of a wide number of scientists are drawn upon in order to interpret what is found; Forensic Pathologists, Forensic Odontologists, Entomologists and Anthropologists are just a few of those who may become involved. The victim's final story can often be told with the information gathered.
Blood is a liquid and is subject to the laws of physics. The patterns left by blood can be interpreted by individuals with the proper training. In addition to interpreting spatter, members can use reagents to detect the presence of blood.
What's with the funny white bunny suits at crime scenes?
In order to ensure that the evidence collected at the scene originates with those present at the time of the crime and not at a later time, FIU members control the introduction of contaminants. Every person who enters the scene can bring with them contaminating transfer evidence picked up at other locations.
Controlling against this introduction of contamination is one reason you might be confronted with the familiar yellow police tape at a crime scene. The funny white suits serve the same purpose, protecting the scene from contaminants that FIU members might bring with them.
DNA is still a fairly new forensic science that continues to develop at a rapid pace. FIU members are trained to properly collect and preserve DNA evidence for analysis by the RCMP Laboratory. As techniques improve, the amount of sample needed to identify DNA is becoming smaller and smaller.
FIU members are trained to detect, preserve and collect fingerprints and then to identify the source of these prints.
There are a number of different types of fingerprints, some of which include visible, latent, moulded, take away and deposited. To detect these prints, FIU members use a variety of techniques, which include the use of powders and florescent powders, alternate light sources and chemicals.
FIU members receive extensive training in fingerprint comparison and become experts in identifying individuals from fingerprints recovered at crime scenes.
Footwear can be identified in much the same manner as fingerprints. When footwear is manufactured, the sole pattern is unique to that shoe or boot style. This pattern is known as a class characteristic. As soon it is worn, footwear develops wear patterns that are unique to the owner and the surfaces walked on, known as accidental characteristics. The uniqueness of these two characteristics can enable footwear to be identified.
If impressions or prints of the suspect's footwear are left at the scene, FIU members can collect this evidence and attempt to compare it to the footwear of a known suspect.
Hair and Fibre Collection
Hair and fibres transfer between the victim, suspect and crime scene. Using a variety of techniques, these items can be collected for later comparisons by the Crime Lab.
FIU members are trained in a variety of photographic techniques in order to record evidence found at scenes and to record procedures used in recovering it. Some of these techniques include:
- night photography
- studio photography
- aerial photography
Scene Measurements & Scale Drawings
Measurement of crime scenes is also a skill required by FIU members. A variety of tools and instruments are used to collect the measurements of each major scene. This information is then used to generate scale drawings, either on a computer using CAD or in some cases on the drafting table by hand.
Tires also have class characteristics and develop accidental characteristics for the same reasons as footwear. Tire impressions can therefore be identified in the same manner.
Tool Mark Castings
Tools can be compared to marks left at crime scenes. FIU members can take castings of marks found at scenes for later comparisons by the Crime Lab.