Earlier this year, a judge from the District of Columbia Court of Appeals wrote an opinion that directly challenged a common practice in criminal courtrooms around the country. Issuing a concurring opinion in the appeal of a murder conviction against a 36-year-old D.C. man, Associate Judge Catharine Easterly wrote that claims by forensic experts that a bullet or shell casing can be unequivocally matched to a particular weapon lack a sound scientific basis and should not be permitted in criminal trials.
Thousands of Convictions
Anyone with any interest in criminal investigations, including readers of mystery thrillers and those who watch crime scene procedural dramas on television, can probably explain with reasonable accuracy the method used to match a bullet or shell casing to a particular firearm. When a slug or shell is found at the scene of a murder or other violent crime, forensic professionals then look for a suspect weapon. After firing the weapon, the technician compares bullets and shells known to have been fired by the gun with those found at the crime scene. If the markings, scratches, and scrapes on each slug or shell match one another, the technician concludes—and testifies—that they must have been fired by the same gun. Such testimony has contributed to the conviction of countless thousands of violent offenders.
Concerns Over “Junk Science”
Over the last two decades or so, there has been growing concern over the reliability of this type of forensic evidence. Washington, D.C., in fact, has not permitted forensic experts to testify that such matches were “absolute” or made with “100% scientific certainty” since 2009 after two separate National Research Council panels could find no supporting statistical evidence for these claims. The panels could not even find a way to prove whether a firearm even produces a unique, distinguishable marks on fired bullets or shells. Judge Easterly pointed out in her opinion that the Supreme Court of Massachusetts already expressly limits firearms experts’ testimony and suggested that other jurisdictions should follow suit.
Other scientists and statisticians agree. A separate committee at the National Academy of Sciences reached a similar conclusion in 2009. “No forensic method,” they found, “has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source.” This includes ballistic evidence, fingerprints, shoe prints, tire tracks, bite marks, and many others.
A New Approach
Although the road ahead will be long and difficult, efforts are underway to develop a new system of analyzing forensic evidence that does not rely on the “expert” opinion that simply states that the connection exists. The National Institute of Standards and Technology and the Department of Justice have deployed a number of working groups tasked with creating standards for the collection and evaluation of criminal forensic evidence. Their plan is to establish a certainty scale which expert witnesses could utilize to describe the empirical likelihood that evidence is or is not linked to a particular suspect, rather than relying upon subjective—albeit educated—opinions.
Disputing Unreliable Evidence
If you have been accused of a violent crime, you need a lawyer who will fight to protect your rights from potentially biased claims and uncertain science. Contact an experienced Hartford criminal defense attorney to discuss your case and to explore the options available to you under the law. Call [[phone1]] to schedule a confidential consultation at the Woolf Law Firm, LLC, today.