Chemical traces on treated fabrics may help investigators solve crimes

U.S. researchers say crime-scene investigators may soon have a new forensic technique to identify individual fibers of cloth, which often look alike. An analysis of chemical signatures on common fibers may help solve crimes, said Brian Strohmeier, a scientist at Thermo Fisher Scientific, a laboratory-instrument company in Massachusetts. "White cotton fibers are so common and have so few visual distinguishing features that they are largely ignored by forensic scientists at crime scenes," Strohmeier said. However, he noted, most of today's fabrics have gone through various manufacturing and treatment processes -- to make them stain resistant, waterproof or wrinkle-free -- which leaves distinct and unique organic chemicals on the surface of the fibers. A variation of a technique called X-ray photoelectron spectroscopy can reveal the chemical signature on the surface of a fiber, he said. Previously, XPS hadn't been used much in forensic science, Strohmeier said, but the technology has improved to the point that analysis now takes minutes and can work with the tiniest of samples. Strohmeier described the research at the AVS 60th International Symposium and Exhibition in Long Beach, Calif.