Lives often hang on Palenik's precise identification of a fiber or fleck of metal. In his workday, there's no room for error.
THE CASE OF THE WELDER'S DUST
The Evidence: In 1991, an 11-year-old girl was raped and murdered near Glennallen, Alaska. On her freshly laundered clothes investigators found flakes of glossy paint, tiny metal spheres and flakes, and red and blue polypropylene fibers. Charles Smithart, a local resident, had been spotted near the murder site, and the unusual interest he took in the case aroused suspicions, but investigators lacked evidence that directly linked him to the crime.