SPECIAL TWO-HOUR 48 HOURS MYSTERY: A TEEN IS CONVICTED OF A GRUESOME MURDER - WILL SOME OF THE INVESTIGATORS WHO PUT HIM BEHIND BARS PROVE HE DIDN'T DO IT? SATURDAY, DECEMBER 24 (9:00 PM, ET/PT)

WHAT: A troubled teen is convicted of a gruesome murder. Now, some of the investigators who put him behind bars want to prove he didn't do it. Could Tim Masters have a happy ending to this saga?

WHO: Peggy Hettrick was murdered in 1987, her mutilated, half-naked body discovered in a field in Fort Collins, Colo. Since then, Tim Masters has lived in the shadow of the brutal crime. At the time of Hettrick's death, Masters was a teenager with a penchant for knives and drawing graphic images of death and mutilation. He immediately became a suspect. Correspondent Susan Spencer reports the story of Masters' case, and what Masters' life is like today in this special two-hour 48 HOURS MYSTERY.

WHEN: Saturday, Dec. 24 (9:00 - 11:00 PM, ET/PT)

WHY YOU SHOULD WATCH: The case against Masters was only circumstantial. Weeks turned into months and months into years, with no arrest. Authorities even planted fake newspaper stories about his imminent arrest in the hopes of goading Masters into doing something incriminating, but to no avail. Then, in 1997, authorities found a new expert witness, one who put a new spin on the little evidence they had. More than 10 years after Hettrick's murder, Tim Masters was convicted - the result of what his attorneys consider to be a single-minded, psychologically relentless investigation by an overzealous cop. And Masters' supporters, including some of the investigators who initially pursued him, believe this case was built not on evidence, but on fear, and they've set out to prove his innocence. It is a search for answers that would take them around the world and expose stunning new suspects. The new investigation would take almost a decade, but would finally reveal shocking new evidence and an astonishing truth that would change everything.

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