Accused Golden State Killer Joseph DeAngelo was cleared this week of a 1978 cold-case slaying of a woman and her young son.

The double slaying in Simi Valley, Southern California, was reopened recently when authorities discovered that Craig Coley, the man who spent 38 years behind bars for the crime, was innocent.

Investigators suspected that DeAngelo — who is accused of 12 murders and more than 50 rapes — might have also killed 24-year-old Rhonda Wicht and her 4-year-old son, Donald.

The young mother was found by relatives after missing a family gathering in Ventura County. She had been beaten, raped and strangled with a macramé rope, while her son was smothered in his sleep.

The killing matched the East Area Rapist’s disturbing M.O. and occurred within the same time frame as his other suspected crimes.

But DNA taken from the crime scene didn’t match samples from DeAngelo, the Los Angeles Times reported this week.

“They conclusively eliminated him as a suspect,” said Simi Valley Police Chief David Livingstone. “Once we follow and exhaust a lead, we move on.”

Coley, who was the young mother’s ex-boyfriend, was pardoned by Gov. Jerry Brown and released from prison on Thanksgiving Eve last year at 71 years old.

The pardon came after the case was reopened in 2016 when retired detective Mike Bender raised doubts that Coley was guilty.

Detectives located a piece of Wicht’s bedsheet with DNA evidence that was thought to have been destroyed. But the DNA from sperm and epithelial cells on the sheet didn’t match Coley’s.

The California Victim Compensation Board voted unanimously that Coley should receive a $2 million payment — $140 for each of the 13,991 days he was wrongfully incarcerated.

Detectives are now turning to other possibilities to solve the crime.

“We don’t leave any lead unturned,” Livingstone said.