S3/EP4 The Daniels family murders in Santa Claus couldn't be comprehended by ordinary citizens, former Deputy Sheriff Ramon Powell says. George State Trooper Keith Horn recalls getting the call.

S3/EP4 Deputy Sheriff Ramon Powell says the Daniels family murders in Santa Claus was the worst crime he ever witnessed. Survivor Amber Daniels recalls her childhood.

S3/EP4 A farmer and his wife in Bacon County were awakened by a dog barking — three young girls in nightgowns stood outside his home. They had survived Jerry Heidler's massacre at the Daniels family home.

S3/EP4 As a foster parent, Kim Daniels would meet with biological parents. Only one made her uncomfortable: Serena Davis, who claimed to be involved with voodoo and black magic.

S3/EP4 The scene where authorities found Kim and Danny Daniels, and their kids Bryant and Jessica, would "bring the strongest man to his knees," a deputy sheriff recalls.

S3/EP4 Deputy Sheriff Mike Harlin recalls doing a welfare check at the home of Kim and Danny Daniels in Santa Claus, Georgia. The place was "hauntingly quiet," he says.

S3/EP3 The small rural community of ranchers and farmers in Locust Grove was shocked and confused by Jack and Elaine Denney's brutal Christmas Day murder. Rumors about drug users went around, but investigators found nothing to support them.

S3/EP3 Prison inmate Justin Walker said he had information on Jack and Elaine Denney's murder. Although he made the unlikely claim that he was hired to do it, he gave information that led authorities to believe he was at least there at the time, former OSBU Agent Vicky Lyons says.

S3/EP3 Jack and Elaine Denney touched so many hearts, friend and neighbor Jessica Copeland recalls. No one believed they had really been murdered. And, their funeral was one of the biggest anyone had ever seen.

Grief expert and author of the book “The Journey Through Grief and Loss: Helping Yourself and Your Child When Grief is Shared” Robert Zucker shares insights on getting through the holidays while grieving someone we love.

S3/EP3 Jack and Elaine Denney's nephew, Billy Scott, told investigators he was likely the last person to see the couple alive. His behavior made him a suspect immediately.

S3/EP3 The scene where Jack and Elaine Denney were murdered looked like a "shootout," former Undersheriff Jason Chennault. No motive could be discerned, and the Christmas Day murders would become a long unsolved Oklahoma mystery.

S3/EP3 Investigators examined the scene where Jack and Elaine Denney were shot to death on Christmas Day. It was likely not a robbery, and the only clue they found was a palm print on a drier.

S3/EP2 Reporter Stacey Deffenbaugh recalls how key witness Kellie Ballew stayed out of the spotlight. She was soft-spoken, but well-spoken, she says, and helped prosecutors lay out a timeline of Steven and Michelle Andrews' murders.

S3/EP2 A crime scene specialist recalls that her team performed tests on Steven and Michelle Andrews' bodies for fingerprints, but weren't able to find anything identifiable.

S3/EP2 Reporter Stacey Deffenbaugh says prosecutors did a great job laying out how Fred Cooper was able to get to Gateway, giving him the opportunity to murder Steven and Michelle Andrews.