Is it Still Possible to Commit the “Perfect” Crime?
Why is Sherlock Holmes associated with a magnifying glass? He is looking for anything at the crime scene that appears out of place, no matter how minute, something he may overlook with the naked eye. Powerful microscopes and imaging devices are the standard “magnifying glass” for today’s investigators. Trace evidence is exactly the type of evidence cutting edge Sherlock is looking for.
To successfully defend his client, a criminal defense lawyer must understand what constitutes trace evidence and how the prosecution will likely use it against his client at trial. Examples of trace evidence include: skin, hair, various residues (including gunshot residues), fingerprints, fibers, pollen, impressions (such as a footprint), fragments (such as glass or paint), or a piece of a broken object. Even the most meticulously careful criminal will leave behind some evidence, no matter how vanishingly small, at the crime scene. New sophisticated imaging devices, evidence gathering techniques, and protocols are helping investigators harvest trace evidence that only a few years ago was undetectable.
Since evolving detection methodologies necessarily precede identification capabilities, trace evidence may provide few actual leads. To the trained eye, unrelated fibers can be microscopically indistinguishable. Investigators often recover only partial or smeared fingerprints. Degraded residues may yield few clues to their origin. Even where identification is possible, contamination – on such a microscopic level – may be difficult to prevent or exclude.
However, from a single fiber recovered from a victim or a crime scene, a talented investigator may discover that it came from a particular garment and create a statistical analysis demonstrating, based on the number of these garments sold within that geographical location, the probability of the victim randomly coming into contact with that garment. A copious investigator may obtain promising leads on the identity of the perpetrator by accessing credit card receipts from nearby stores selling the garment.
With all the advances in crime detection methodologies, equipment, and data bases, the “perfect” crime may one day soon be a relic of the past.
Kevin J. Mahoney is a Cambridge, MA Criminal Defense Lawyer.
