12 Crime Lab Tidbits

by Vinnie Hansen

In March, I visited the Santa Clara Crime Lab because hey, that’s the kind of thing crime writers do on a lovely spring day.

My husband, Danny, went along. He enjoys police info, too. I guess you better if you’re married to a mystery author.

We were disappointed to learn that we would not be able to traipse about the lab. Even though the event was advertised as a “virtual” tour, when Danny and I visited the FBI Crime Lab in San Francisco, our guide led us right up to the line of weapons waiting for rifling tests. But that was many years ago and our group consisted of just Danny, Cara Black and me.

Criminalist Cordelia Willis

Criminalist Cordelia Willis

The Santa Clara Crime Lab presentation drew over 20 sisters and misters from NorCal Sisters in Crime as well as a whole class from a local college. I was glad that criminalist Cordelia Willis did not try to herd such an unwieldy flock.

But even if there were only a few of us, we could not have entered the lab. Our very breath could contaminate DNA evidence!

Instead, we congregated in the training room for slides and an informative talk.

Here are a dozen fun facts from our two-hour stint:

  • The bane of criminalists: lawyers, lawyers, lawyers, and EMTs who trample evidence.
  • CODIS (Combined DNA Index System) has two parts, the usual one we think of which contains info only from criminals, and another part for unidentified persons, used to match bodies to missing people. The criminal and victim parts do not mix.
  • Red Bull is the drink of choice for burglars (and a nifty way to collect DNA).
  • Thirty is the magic number when a murderer stabs his victim.
  • A slice on the perpetrator’s hand is common in stabbings because the knife handle gets slippery. (Think O.J.)
  • Cordelia worked on a cold case where DNA evidence was taken from 22- year-old semen.
  • If a body is inside a structure, the police have to get a search warrant to call in the lab.
  • Digital/multimedia evidence is most backlogged. One case might yield 15 cellphones!IMG_1418
  • Bullet rifling is unique to each individual gun, but (sigh) many bullets get smooshed and can’t be tested.
  • BUT, cartridges can be compared via the firing pin impression.IMG_1420
  • Gun shot residue disappears quickly — no sense testing after 8 hours.
  • It’s blood spatter, not blood splatter.

Have you ever wondered how much of CSI is true? What’s a question you would like answered by a crime lab? 


Posted by Vinnie Hansen.


Vinnie is a retired English teacher and award-winning author. Her Carol Sabala mystery series is set in Santa Cruz, California.

Her forthcoming book, Lostart Street, is a stand-alone novel of mystery, manslaughter and moonbeams.

Here’s a sneak peak at the cover. If you saw the cover in the last post, you’ll notice the new iteration is slightly different. What do you think?


We blog here at misterio press once (sometimes twice) a week, usually on Tuesdays. Sometimes we talk about serious topics, and sometimes we just have some fun.

Please follow us so you don’t miss out on any of the interesting stuff, or the fun! (We do not lend, sell nor otherwise bend, spindle or mutilate followers’ e-mail addresses. 🙂 )

You Might Also Like


  • Reply
    Shannon Esposito
    April 25, 2017 at 10:01 am

    What…Redbull??? Like the criminals leave cans of the stuff behind? Interesting about the gun powder residue, didn’t know it disappeared so quickly.

  • Reply
    Vinnie Hansen
    April 25, 2017 at 11:19 am

    When Danny and I were burglarized, our burglar was linked to another crime via a left-behind Big Gulp. The every-day, run-of-the-mill thief is often not so bright. Which I guess is a good thing?

  • Reply
    Kassandra Lamb
    April 25, 2017 at 11:57 am

    Gun residue disappears quickly huh? Dang, now I’ve got to revise something in my WIP.

    Great post, Vinnie!

  • Reply
    Vinnie Hansen
    April 25, 2017 at 12:11 pm

    “Half my life is an act of revision.” — John Irving 🙂

    • Reply
      Kassandra Lamb
      April 26, 2017 at 1:45 am

      Sad but true.

  • Reply
    Dwayne Keller
    April 25, 2017 at 9:12 pm

    Very interesting article. Thanks for sharing.

    • Reply
      Vinnie Hansen
      April 25, 2017 at 11:07 pm

      Thanks for dropping by, Dwayne.

    • Reply
      Kassandra Lamb
      April 26, 2017 at 1:45 am

      Glad you liked it, Dwayne.

  • Reply
    Olga Núñez Miret
    April 26, 2017 at 2:14 pm

    Very useful. Thanks very much!

  • Reply
    Vinnie Hansen
    April 27, 2017 at 2:17 pm

    Thanks for dropping by, Olga. If you have any questions, please feel free to ask and I’ll see if the topic was covered. I could easily have listed twice as many tidbits. 🙂

  • Leave a Reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.