LOS ANGELES, Nov. 19 – The confessed killer of Hollywood producer and acting coach Laurence Merrick was found not guilty of Merrick’s murder Thursday by reason of insanity, and ordered committed to a state mental hospital, potentially for the rest of his life.

Dennis Mignano, 35, of San Jose gave police in that city an unsolicited confession that he had killed Merrick, four years after the producer was shot to death in the parking lot of his Hollywood film school on Jan. 26. 1977.

Within days of his confession, Mignano was taken to Los Angeles, where he was charged with the unsolved slaying.

Mignano, an unemployed would-be actor and singer with a long history of psychiatric problems, claimed he had auditioned at Merrick’s school and that, during the audition, “black magic” spells were cast upon him that later caused him problems, according to Deputy Dist. Atty. Harvey Giss, who prosecuted him in the murder case.

Mignano claimed in his confession that he traveled by bus from San Jose to Hollywood to see Merrick because he felt Merrick had destroyed his voice and made him physically shrink in size, said Deputy Public Defender Alvin Nierenberg, who defended him.

Nierenberg said Mignano related that he wanted for Merrick to come out of the school, then spoke with him. When Merrick, 50, turned away, Mignano fired his gun once, claiming that he intended to hit Merrick in the leg. The bullet entered Merrick’s lower back and killed him.

In a non-jury trial, Los Angeles Superior Court Judge Gordon Ringer first concluded that Mignano had in fact fired the shot that killed Merrick. Ringer ruled that the killing was second-degree murder with a gun, a crime punishable by imprisonment for 10 years to life.

Then, in a separate phase of the trial, Ringer heard unanimous psychiatric testimony that Mignano was insane at the time of the murder and remains insane. Ringer then judged Mignano not guilty by reason of insanity and ordered him committed to a mental hospital for life.

Prosecutors said state mental hospital officials could decide to release Mignano, despite Ringer’s order, if they later determine that Mignano has regained his sanity. But Nierenberg noted that the district attorney’s office could challenge any such decision in court.

By TED ROHRLICH