20 years later: What led Cary Stayner's unspeakable crimes

Cary Stayner made headlines in 1999 after he terrorized Yosemite National Park, murdering tourists Carole Sund, her daughter Juli Sund and friend Silvina Pelosso, along with park naturalist Joie Armstrong

Titled *Evil in Eden* -- 20/20 revisits one of the biggest news maker stories in recent history through a modern lens in Friday's two hour special.

Including many exclusive interviews and news footage taken from the Action News archives.

"It was just one of those stories that you couldn't believe the horrific acts that were happening in one of the most beautiful places on this planet," said Amy Roback with ABC News.

20/20 also tells the story about Cary's younger brother Steven, who was kidnapped in Merced as a child and escaped after seven years in captivity. Steven's disappearance may have impacted Cary's behavior.

"This to me was the most fascinated aspect to this story did what happen to his family starting back in 1972 lead to these horrific acts in 1999," Roback said.

Cary committed the gruesome acts of violence over a six month period while working as a handyman at Yosemite Cedar Lodge.

When he was eventually brought in for questioning, Cary confessed in detail about how he killed his victims.

A look at Cary Stayner shows an aging man over the years.

He was sentenced to death and is currently on death row at San Quentin State prison