The use of forensics in television dramas has created a legal phenomenon known as the “CSI effect.” Jurors today often view forensics as gospel based on what they see on their favorite shows. The August issue of Popular Mechanics magazine attempts to dispel some myths in a cover story entitled, “The Truth About Forensics”.
In real life, many forensic labs are understaffed and have a huge backlog of requests for services. Some state and city forensic departments have mishandled evidence, and since no advanced degree is required for a career in forensics, personnel with minimal credentials staff many of the labs around the country.
But a more serious issue emerged last February when the National Academy of Sciences issued a report noting that, “apart from DNA, there is not a single forensic discipline that has been proven with a high degree of certainty to be able to match a piece of evidence to a suspect.”
While DNA is considered the gold standard of identification, a debate is growing between defense attorneys and forensic experts concerning the scientific validity of fingerprints, footprints, tire tracks, bite marks, blood-splatter patterns, ballistics, hair, fiber, and handwriting analysis. Evidence such as voiceprint analysis and lead analysis of bullets already has been completely discredited.
According to the article, despite the widespread belief in the accuracy of fingerprints, “no studies have proved definitively that fingerprints are unique, and it’s unclear if prints change over time or vary depending on the amount of pressure applied.” Studies quantifying the probability of error in ballistics matching also should be done. Currently, it’s impossible to say with certainty that the marks made on fired bullets are unique to an individual gun.
Alternately, paint analysis has a relatively strong scientific backing and can provide reliable results. While fiber analysis has a foundation in chemistry, more research is needed to determine the criteria for a match. The article points out that current methodology is only sufficient to conclude that fibers could have come from the same type of garment or carpet. Research has also shown that matching hairs using subjective analysis can be highly inaccurate.
Software to help quantify the certainty of fingerprint matches is currently being developed, as well as a database of microscopic tool marks to give statistical significance to the identification of burglars’ tools. But it appears that more forensic research needs to be done. As a writer of police procedurals, forensics often plays a role in the solution of my fictional crime stories. Since I want my novels to be as accurate and believable as possible, I’ll continue to follow the latest research. Hollywood should do the same.
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