Monday, September 9, 2013

Writers' Police Academy Day 1 (Part 1) - Fingerprinting


Yesterday was the first full day of Writers' Police Academy 2013 and I had a great time.  It really is an exceptional event, especially if you want to write about crime and law enforcement but don't have the luxury of having any cops in your family or circle of friends.

What I learned at WPA:

Fingerprinting (Instructor: Michelle Davis of the Greensboro, NC Police Department)
  • Latent = invisible to the naked eye.
  • Latent prints are collected by crime scene techs and delivered to the fingerprint tech.  Elimination prints (PD, EMS, witnesses) are also collected, as are post-mortem prints from the victim.
  • Cases are prioritized, with homicides getting top priority, followed by B&E's (breaking and entering) and vandalism.
  • Can get a hit in as little as 2 minutes or as long as two days.
  • Expungements: If prints have been entered into the system and then the charges are dropped or the suspect has been found not guilty, the prints must be removed from the system.  
  • Pattern classes of fingerprints are described as arches (rarest), whorls, and loops (most common). 
  • Women and children have finer fingerprint ridges than men.
  • Fingerprints are made up of sweat/water and oil. The sweat evaporates, the oil does not. Clean, dry hands result in lesser prints. Too much lotion on hands can result in a smudged print.
  • Identical twins have identical DNA but not identical fingerprints.
  • Certain types of work (brickwork, handling certain chemicals) can result in poorer quality of prints.
  • Fingerprints are very delicate, so wiping them to hide your crime is actually very effective.
  • Scars on fingertips are very helpful in making an ID. Law enforcement loves it when scars turn up.



We got to watch a fingerprint identification program search for a match to a print Michelle entered into the system.  It looked nothing like the graphics-happy systems on TV shows, rather it's a very plain, Windows based pane.  No picture of a driver's license or criminal record information pops up. Just a single line of text per match.

What a match really looks like.  If you want to be 
a CSI like on TV, study acting, not forensics.

We also got to dust and lift our own prints from a piece of tile and a jar that we touched.  Here's the evidence of my criminal activity.  Busted!

Prints dusted.
Prints lifted.  You have the right to remain silent...

More fingerprinting pics can be found here.

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