Was alleged Golden State Killer behind Rhonda Wicht and her son's murder?

SIMI VALLEY, Calif. -- California police are investigating whether the suspected Golden State Killer is responsible for a double-murder that sent an innocent man to prison. Rhonda Wicht and her 4-year-old son, Donald, were killed in their apartment in 1978. Her ex-boyfriend, Craig Coley, was exonerated last year after nearly four decades in prison.

DNA proved 70-year-old Coley was not a murderer, reports CBS News correspondent Carter Evans. It also unmasked Joseph DeAngelo as the alleged Golden State Killer. Now detectives here are turning to DNA evidence once again, hoping it can solve a 40-year-old mystery once and for all.

"They were dear to me. I loved them, and I never had time to grieve their death," Coley told Evans. Coley spent more than half his life behind bars for a double homicide he didn't commit.

Now investigators are wondering if the crime might be linked to DeAngelo, suspected in 12 murders and more than 50 rapes across California. Wicht was raped and strangled, and her son was suffocated.

"Do you think the Golden State Killer could be responsible?" Evans asked.

"That's a possibility. I think that there are other suspects that are more likely," Coley said.  

"What if he does turn out to be the killer?"

"Well, it'll be solved. Maybe the family can rest. Maybe they can relax," Coley responded.

"How about you?"

"I could care less about him," Coley said.

Simi Valley police have asked for a comparison of DeAngelo's DNA with Wicht's actual killer.

"The DNA will tell the true story. Once it's compared, we'll be able to tell whether or not he was involved," said Joseph May, the department's deputy chief.

DeAngelo has already been charged with two murders in Ventura County where Simi Valley is located. He allegedly killed Lyman and Charlene Smith in 1980, two years before Wicht and her son were murdered.

"If it doesn't come back a match, we have other leads that we're looking at. One thing is, it'll be good that we know we've eliminated a suspect," May said.

Last year, police recovered long lost crime scene evidence and tested it for DNA, technology not available at the time of Coley's trial. The results ruled Coley out as the murderer.

Former Simi Valley detective Michael Bender helped win Coley's freedom. He quit the police department in 1991 because he was convinced Coley was innocent – and devoted his life to trying to prove it. He's also curious about DeAngelo.

"Knowing everything you know about this investigation, in your heart of hearts, do you think that DNA is gonna match?" Evans asked.

"I would be surprised," Bender said. "But I'm happy to be wrong."

Wicht's sister is also skeptical the DNA will match. She told CBS News: "Based on what we know of the Golden State Killer's MO, it is probably doubtful, but with so many unknowns in his history it's definitely a positive step." Deputy chief May called it "a longshot."