A 10-week-old fingerprint was 'lifted' with the help of a fluorescent dye and a 5-W diode-pumped laser.
Ten-year-old Anthony Martinez was abducted and killed last April, and his nude, bound body dumped in a remote desert site in Berdoo Canyon, Calif. Despite an intense investigation, few clues to the identity of the boy's brutal killer have turned up.
But the first real break in the highly publicized case may have come from a fingerprint discovered at the crime scene through the use of a forensic application of photonics, Riverside County sheriff's deputies say.
The 10-week-old fingerprint was "lifted" by the forensics unit of the California State Department of Justice in late June, using a fluorescent dye and a 5-W, 532-nm diode-pumped Millennia laser produced by Spectra-Physics Lasers of Mountain View, Calif.
Since the print was found on evidence that had not been handled by police, deputies are hopeful the print belongs to the killer. Sheriff's Sgt. Mark Lohman declined to identify the piece of evidence on which the print appeared.
At press time, authorities were still trying to find a match through a computerized search of existing state felony registries, which include registered sex offenders and other known criminals.
Because of the nonporous surface on which the print was found, and the length of time that had elapsed since discovery of the body, the print could not be lifted by traditional means. That involves dusting the surface with a black powder, which preferentially sticks to the print configuration. Adhesive tape is used to lift the print from the surface, and the impression is placed on a white card to provide maximum contrast. But for this method to work, a print must be fairly fresh, and it cannot be lifted from textured, oily or sticky surfaces.
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