Putting the Science into Forensic Science
During criminal trials, years of a defendant's freedom, or even his or her life, depend in part on the evidence that forensic scientists present. Yet not all forensic science is well tested, which leaves innocent people vulnerable to wrongful convictions. Now, a few ongoing studies aim to bring stricter scientific standards to two forensic techniques: identifying weapons and bite marks.
In a longer feature this week, the chemists' magazine Chemical & Engineering News covered the varying scientific validity of evidence used in criminal trials. The magazine interviewed people who had been freed by DNA evidence, which is the soundest evidence available to courts, after being convicted on shakier scientific ground. It also reported on a call from the Innocence Project, a nonprofit legal clinic that applies DNA testing to convicted cases, for chemists to get involved in court science.
Some chemists are already involved, it seems. City University of New York quantum chemist Nicholas Petraco is studying how to better analyze cartridge cases, which forensic scientists now use to determine the type of gun used in a crime. He uses a computer program and high-tech microscopes to create a 3D model of the cartridge's surface. His research isn't yet court-ready, Chemical & Engineering News reported.
Meanwhile, another research team is trying to validate bite mark analysis. Forensics assumes that bite marks are unique, but there aren't studies to back up that idea, C&EN reported. Dentists at the State University of New York are gathering data to check the individuality of tooth arrangements. They're also clamping casts of teeth onto cadavers.
"The results thus far, which have already been introduced in a handful of hearings, indicate that bite-mark analysis should be undertaken with caution because multiple suspects could have similar teeth," C&EN wrote.
Improving forensic science will be a slow process, forensic chemist Thomas Brettell told CE&N. Brettell teaches at Cedar Crest College and previously worked for the New Jersey State Police Office. Change will require training, money and understanding between the legal community and forensic labs, he said. Yet, he added, "Everybody has the same goals in mind."
Source: Chemical & Engineering News