THREE FRIENDS COVER UP A GRUESOME CRIME UNTIL THEY'RE BETRAYED BY AN UNLIKELY INFORMER ON "48 HOURS MYSTERY," SATURDAY, SEPT. 30

On October 13, 2002, 18-year-old Jim Morel was entrusted with a horrific secret -- one that could send his best friends to prison for life. He shares his story of murder, morality and betrayal with correspondent Susan Spencer on 48 HOURS MYSTERY: "The Informer," to be broadcast on Saturday Sept. 30 (10:00-11:00PM, ET/PT) on the CBS Television Network.

Jim grew up in Norton, Mass., a working-class town near Boston, where he met Anthony Calabro, Jason Weir and Tom Lally. The foursome bonded like a family and were supportive of Jim's band, Electronic Kill Machine. Jim described the band's sound as shocking and aggressive -- a reflection of their attitude that they were untouchable.

On Dec. 19, 2001, 84-year-old retired hairdresser Marina Calabro of Quincy, Mass., died, apparently from an accidental fall down a flight of stairs in her home. Her live-in nephew, Anthony, then 18 years old, called police and reported finding his aunt's body at the foot of the steps. When investigators arrived at the house, they found Marina Calabro in a fetal position with a bad head wound. The medical examiner later confirmed what appeared to be true -- her death was an accident.

Ten months later, another very different story started to emerge when Jason decided to share a dark and troubling secret with Jim -- that Marina Calabro did not die accidentally, but rather that she was beaten to death by their friend, Tom. Jason explained that Marina was killed so that Anthony could inherit her estate. He told Jim they staged the murder to look like an accident.

The news was shocking; Jim was stunned. Could his friends really have murdered an 84-year-old woman? Jason's disclosure of this brutal crime would force Jim to make a choice that could surely ruin the lives of his best friends.

48 HOURS MYSTERY: "The Informer" is produced by Gail Zimmerman and Ian Paisley. The senior producer is Anthony Batson, the executive editor is Al Briganti, and the executive producer is Susan Zirinsky.