Tuesday, May 31, 2011

(empo-tymshft) The no-CSI effect

I have set my Google Reader to search for all sorts of information, and it recently turned up this recent blog post that mentioned a former employer of mine, Printrak. Specifically:

Mucho menos habitual es que una huella latente tomada de un vaso o de la empuñadura de un cuchillo encaje con alguna registrada en la base de datos del Printrak, pero la mayoría de los inspectores pueden contar con los dedos de una mano los casos que han sido resueltos por el laboratorio.

I read further, and found that this was a quote from the libro called Homocidio, written by that famous Hispanic author David Simon.

I don't know why, but I got the feeling that I was reading a translated version of the original quote. I found the original text at the Baltimore Sun website. Here's the English version of the sentence above:

On rare occasions, a latent print taken from a drinking glass or knife hilt will match up with someone's print card in the Printrak computer, but most detectives can count on one hand the number of cases made by lab work.

It turns out that the David Simon book was written twenty years ago. I'm not sure what motivated La Cancion de Malapata to quote from it this year, but have things changed in the intervening decades?

After all, you have a ton of TV shows that show these amazing new forensic technologies, and you have people like me running around and telling you that our forensic systems are the greatest thing since sliced bread - and by the way, we've just added bread knife detection to our product so that you can determine which knife actually sliced that bread.

And you'll get the results in less than 60 minutes (including commercials).

Well, despite the advances in forensic science, the reality is that the number of cases solved by forensic science isn't all that great. Just ask Keith O'Brien:

A study, reviewing 400 murder cases in five jurisdictions, found that the presence of forensic evidence had very little impact on whether an arrest would be made, charges would be filed, or a conviction would be handed down in court.

A mere 13.5 percent of the murder cases reviewed actually had physical evidence that linked the suspect to the crime scene or victim. The conviction rate in those cases was only slightly higher than the rate among all other cases in the sample. And for the most part, the hard, scientific evidence celebrated by crime dramas simply did not surface. According to the research, investigators found some kind of biological evidence 38 percent of the time, latent fingerprints 28 percent of the time, and DNA in just 4.5 percent of homicides.


So if forensics isn't finding most of the bad guys, how are they being found?

Analyzing 400 murder cases committed in 2003 in California’s Los Angeles County, Indianapolis, and three smaller Indiana cities, the researchers found that cases were more likely to end up in court if witnesses came forward or if the victim and the suspect knew each other. Such factors made cases easier to solve and, apparently, easier to prosecute, according to the research, while, on the other hand, forensic evidence was “not a significant factor.”

If you take a minute and think about it, this makes sense. We have this image stuck in our minds of a criminal seeking out victims that he or she has never seen before. But a lot of crimes, including crimes such as rape, occur in cases in which the criminal and the victim knew each other. When you can establish motive, how important can that smudged fingerprint be?

In addition, it needs to be stated - at least for my particular branch of forensics - that if criminals would simply wear gloves, my workload would be significantly reduced. I guess that's why they call it "dumb crime."
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