Deep breath….. I am taking a rare step into the Macabre.  Inspired by Mary Roach’s Stiff and recent scientific evidence, I would argue that the perfect crime may some day be committed by a scientist.  Not that scientists are by nature drawn to criminal or violent acts…but extensive knowledge of sciences like criminology, forensics, or psychology would certainly benefit someone with a deep understanding of them.

Recent findings from the University of Colorado at Boulder point to the latest case-solving tool for forensic scientists: the individuality of hand bacteria.  Similar to standard fingerprints, lip prints or DNA fingerprinting, the genetic make-up of commensate flora on the surface of our hands is apparently a unique signature that is more similar to our own hand bacteria than other people’s  Apparantly, our hands carry about 150 different species of bacteria, but only about 13% match the person’s next to us – leaving a large combination of unique bacteria available for identification.

So, Step 1:  When committing a crime, do not leave behind any of your skin’s bacterial community.  Cover all areas of skin and do not touch anything without gloves.

In other research news, Lawrence Livermore Laboratory has developed forensic methods for determining where or who created toxic warfare chemicals (such as mustard gas, rat poison or nerve agents).  As there are several routes in synthetic chemistry to lead to the same final compound, there are also ways of determining which methods were used to obtain the final compound in question (ie: by-products, impurities and unreacted ingredients) – and therefore helping to pinpoint the origin of the chemical.

Step 2:  if creating any hazardous chemicals – do not purchase the ingredients yourself and ensure no chemical residue remains on your skin, clothing, or belongings.

More and more forensic science is doing the work of freeing those behind bars, not just providing compelling evidence to put them there.  One new breakthrough in this area is an improvement in fingerprinting software, which now will decrease the instances of false positives.  To do this, scientists at UCLA developed software based on 12,000 people’s fingerprints – each taken over 700 times to determine intrapersonal variation.  Another improvement in fingerprinting is the new ability to obtain fingerprints from metal, even after they have been washed with soap and water.  An excerpt from the study’s lead scientist, Dr. John Bond at the University of Leicester:

"The procedure works by applying an electric charge to a metal - say a gun or bullet - which has been coated in a fine conducting powder, similar to that used in photocopiers.

"Even if the fingerprint has been washed off, it leaves a slight corrosion on the metal and this attracts the powder when the charge is applied, so showing up a residual fingerprint.

"The technique works on everything from bullet casings to machine guns. Even if heat vaporises normal clues, police will be able to prove who handled a particular gun."

Finally, Step 3: Do not leave behind fingerprints, and if you do – remove the item, do not just wash with soap and water.

Bottom line: there IS no perfect crime, as long as science continues to find ways to track criminal behavior back to its source and to prevent crimes before they happen. 

Additionally, the recent proposal by President Obama to create a national DNA depository (whether people have committed crimes or not), may be another way to speed up the process of forensic science after a crime is committed.  Conceivably, DNA (including from our skin bacteria) could be deposited in a searchable bioinformatics database, making available only a stretch of DNA unique to an individual without allowing any sensitive DNA information (such as your potential for heritable diseases) being made available.  However, this still leaves the time needed to sequence the DNA of a suspect first – its not as quick and clean as TV shows like CSI make it seem…

For other Forensic News, check out this service from Science Daily:

http://www.sciencedaily.com/news/matter_energy/forensics/

Or this service for Forensics professionals:

http://www.forensicsinthenews.com/

Criminology Resources:

http://www.newcriminologist.com/home.asp

For Fun: Test your own skills in Blood spatter analysis:

http://www.newscientist.com/article/dn16665-csi-new-scientist-test-your-bloodstain-analysis-skills.html

Resources for news stories above:

http://www.sciencenews.org/view/generic/id/57561/title/Better_sleuthing_through_chemistry

http://colorado.edu/news/r/f7ac86fdf8c68f6ed4b7fb1bd9eeca37.html

http://www.nytimes.com/2010/03/15/opinion/15seringhaus.html

http://esciencenews.com/articles/2008/06/02/new.fingerprint.breakthrough.forensic.scientists