I had the opportunity to do a virtual tour of the Santa Clara County Crime Lab recently. I thought perhaps there would be eight to ten people show up, but there were about seventy five attendees. A large group of seniors joined the presentation eager to hear how the real crime lab measures up to Hollywood.
Despite what we all see on TV, the crime lab has four responsibilities: 1) To prove or disprove investigative theories 2) Provide legal proof in the courts as expert witnesses 3) Assist police in the development of suspects and 4) Assist at crime scenes. They testify in court to the evidence and not to the prosecution.
Our criminalist said that they aren't often called to crime scenes. Primarily they attend homicides and crimes where there is a lot of blood. If there is a lot of evidence at a crime scene, they'll spend two days and take over 500 pictures. Crime lab staff do not interact with victims or families as that's the role of detectives.
From a historical point of view (1890's to 1900s) police used a series of measurements to individually identify someone. These measurements at the time were thought to be unique and consisted of such things as wingspan, length of fingers etc, then fingerprints were found to be the unique identifier and were used to identify convicts. Now of course fingerprints are used throughout the criminal justice system as well as for our security efforts.
Our criminalist talked about how stupid most criminals are. They'll wear gloves to the crime scene and then discard them before exiting leaving their DNA behind in the gloves. I might have to make my thugs dimmer in my next book!
Another task they perform is the verification that substance in a baggie in your possession is table salt or is it cocaine. She also verified that they spray superglue on things to find prints, so that is at least one thing that is true about television shows.
One final area of interest was DNA searches. They do not routinely match DNA with Europe (Interpol) because the U.S. uses a different part of the DNA strand for identification purposes (You can bet that will end up in a story line in the future). A local search of the DNA database is quick, but a nationwide search could take hours.
All in all it was a great tour with a lot of interesting information for both the average citizen and the mystery writer.