Minot Police Crime Scene Response Unit explains investigative procedures
Police Citizen’s Academy holds second session
The Crime Scene Response Unit is called upon by Minot Police when necessary to secure a crime scene and conduct an initial investigation. What the Response Unit does and some of the methods they use were presented at the second session of the Police Citizen’s Academy held Tuesday evening at the City Auditorium.
Carmen Asham, Minot Police, told attendees about the make-up of the Crime Scene Response Unit. The unit consists consists of eight PD officers. It is their responsibility to obtain as much evidence as possible from a crime scene, from photographs to physical evidence, and to make a detailed listing of each photo or item.
About criminals and crime scenes Asham said, “Every person who enters an area takes something with them or leaves something behind.”
The task of the Crime Scene Response Unit is to discover the evidence, some of which may be very minute or invisible, and present it to investigators assigned to the case. Their work supplies investigators with necessary information to help piece together what happened, how it happened, and to do so in a manner that is presentable and understandable to a jury if necessary.
Evidence, said Asham, is divided into two categories – trace and associative. Trace evidence is material in nature. Blood and DNA are examples of associative evidence.
Most crime scene evidence is forwarded to the State Crime Laboratory in Bismarck. Since the Bismarck lab is the only such facility in the state and is used by all police departments in North Dakota, the turn-around time for submitted evidence can take six weeks or longer. There’s also a limit as to how many items of evidence can be submitted for any single crime, no matter how much a response unit may have gathered.
An example given at the Tuesday session was of a murder investigation in Minot in which there were 148 items of evidence. From those 148 the State Crime Lab would only accept five, the maximum allowed, meaning investigators had to be extremely selective in which items of evidence they chose to submit to the State Lab for analysis.
Various methods of obtaining fingerprints from a crime scene or select items were demonstrated. So too were methods of retrieving DNA from an item or location. While DNA is considered very conclusive, the database for comparison is much, much smaller than what is available for fingerprints.
In crime scenes where a firearm was used, investigators showed how they utilized bullet trajectory analysis to determine where the shooter was when the shots were fired and even get an estimate on the height of the shooter. Another demonstration was of tire tracks and how they can help identify a vehicle that may have been used in a crime.
Photographs, said investigators, are the first consideration in collecting evidence. High quality photographs are made of the crime scene and of each item of potential evidence before any further investigative procedures commence. Photographs provide investigators with a valuable record of evidence in the event that collecting or analysis of any crime scene evidence is compromised.