MARSHALL - When called to a crime scene, the job of law enforcement is to record the testimony of witnesses, if any, and collect physical evidence. But physical evidence is often fragile and without careful preservation can be contaminated or destroyed before it ever gets to a crime lab.
On Tuesday, Minnesota West Community and Technical College brought three experts from FBI regional headquarters in Minneapolis and Sioux Falls, S.D., for an all-day training seminar on gathering and preserving evidence.
About 25 law enforcement local and regional law enforcement officers attended lectures and hands-on demonstrations on methods and procedures for fingerprinting, blood and body fluid collection, DNA sampling, footprint and tire impression casting, packaging and preserving evidence, testifying in court and the so-called "CSI effect."
The course was organized by Matthew Loeslie, law enforcement training director at Minnesota West.
"It's to help officers to collect evidence," Loeslie said. "Most crimes are solved by interviews, but if you can't get the suspects to talk, this give you alternative means."
Jay Brunn is the training coordinator and team leader of the Evidence Response Team (ERT) at the FBI Minneapolis Field Office.
"With all the advances in forensic science, it's really important to provide this type of training and it's part of our mission," Brunn said. "With trained first responders, the first on the scene, there's more of a chance the evidence will be collected and preserved."
According to Brunn, the seminar is an abbreviated version of an 80-hour course offered by the FBI.
An FBI office or big-city police department may have the resources for a Crime Scene Investigation team as seen on the popular TV show, with specialists for different functions at the scene. But small-town police departments and rural sheriffs' offices have neither the budget nor the personnel, so they need a high level of training in evidence gathering. Once the evidence is preserved and the chain of custody documented, it can be analyzed by crime labs of state and federal agencies.
Jeff Merrill was one of four deputies from the Emmet County, Iowa, Sheriff's Office attending.
"It's a crucial reminder of the importance of evidence preservation," Merrill said. "There's a lot of expertise here."
David Keith of the Minneapolis FBI office specializes in photography. Keith stressed it's particularly important to photograph a piece of evidence before it is moved.
"You take as many photos as you can," Keith said. "The thing with a digital camera you can look at what you got. With film, you don't know what it is. Then you take the card and download it to a CD."
Lori Corso from the Sioux Falls regional office taught the importance of packaging evidence to preserve it and avoid contamination. Though laboratory science has advanced a lot in recent years, the best scientific analysis means nothing if the evidence is destroyed or damaged.
"This is going to be short and sweet," Corso said. "If you have wet evidence - dry it out."
Any materials containing body fluids with DNA must be dried out, according to Corso, because wet samples can quickly become moldy. And mold, like all living things, has its own DNA.
If collecting and analyzing evidence are two legs of the tripod, the third is presenting the evidence in court to a jury of citizens who are probably not scientists. This is where the so-called "CSI effect" comes in, a popular impression created by the crime lab television shows.
"For good or bad, a lot of people see them and get their impression of forensic science from them," Brunn said. "Prosecutors have found juries expect things like fingerprints, and unfortunately they're not always there. The important thing to remember that what we're testifying in court is not opinion. Do a good job describing where a particular item was found, how the evidence was gathered, processed and the smooth handoff to the lab and it'll make you look more professional to a jury."