On October 1, 1993, a stranger abducted 12-year-old Polly Klaas during a slumber party in her home.  The FBI was immediately called in.  Agents collected fibers from her bedroom and discovered, through the use of laser light sources, a palm print on Polly’s bed, previously invisible to the naked eye.  After a massive two-month investigation, the FBI arrested Richard Allen Davis.  Palm prints and fibers matched and Davis was convicted of abduction and murder.