A body unidentified for 30 years. A 15-year-old murder that had a suspect, but not enough evidence for trial. A murder victim whose killer was never found. All three of these cases have one thing in common: new technology is helping to unlock their secrets, bringing relief to worried family members and justice to the criminals. CBS News 48 Hours shows, in three dramatic stories, how new technology is helping investigators solve old crimes, mysteries that were once thought to be unsolveable. They include the identification of a dead woman known only as "Tent Girl," the unsolved murder of a teenager from a quiet town, and the shotgun death of a college student. The Story of Tent Girl: How the Web helped solve a 30-year-old case. The Telltale Shotgun Shell: Scientists try to solve a 15-year-old murder. Who Killed Laura Long?: DNA tests may warm up a murderer's cold trail.