Frank O'Connell could still face a new trial, the Los Angeles Times reported.
Los Angeles County Superior Court Judge Suzette Clover vacated his conviction last month, ruling that investigators had failed to turn over potentially exculpatory evidence to the prosecution and defense.
Clover set bail at $75,000, the same amount set when O'Connell was first arrested. The bail had been posted late Friday but he remained in custody.
Jay French, who was involved in a nasty custody fight with his ex-wife, was shot in 1984. A witness described a man closely resembling O'Connell but has said more recently that he was not wearing his glasses at the time, barely saw the man and felt pressured by investigators into making a positive identification.
Several members of French's family attended Friday's hearing, including the woman he was married to when he was killed. They said they believe O'Connell was the killer.
"The pain will never stop," said Gina French, who was pregnant at the time with a son who is now 27.
O'Connell's mother and sisters said they feel sympathy for the French family.
"Our nightmare is over, but theirs is not," a sister, Kathy Baker, said.