Los Angeles police are urging the public to come forward with any information about the three unknown suspects wanted in the killing of former "General Hospital" actor Johnny Wactor.
The 37-year-old actor was shot around 3:25 a.m. Saturday, after he ended his shift at a downtown Los Angeles bar and walked to his car, according to the Los Angeles Police Department.
He was confronted by three people who had his car "raised up with a floor jack and were in the process of stealing the catalytic converter," police said in a statement.
Wactor's family and friends said the actor was with a female co-worker, and he immediately stepped in front of her to try to protect her.
MORE: Johnny Wactor's family speaks out after 'General Hospital' star fatally shot: 'They took a wonderful person'"They had a mask on and they pulled out a gun," Wactor's friend, Colin Flynn, told ABC News. "And from what I understand, Johnny literally stood in between himself and his colleague. And the shooter just pulled the trigger and ran away."
Wactor was shot "without provocation," police said.
"Johnny's just an unbelievable friend," Flynn said. "Such a humble, loving, passionate person. He did tons of service to help other people."
As police search for the three unknown suspects, Jim McDonnell, former Los Angeles County sheriff and current director of the Safe Communities Institute at the University of Southern California, said investigators should be combing the area for surveillance cameras.
"At some point, [the suspect] put that mask on -- when was that? Are you able to get any footage that would show that?" McDonnell told ABC News.
MORE: 'General Hospital' actor Johnny Wactor shot to death in Los AngelesThe suspects also may be sharing details of the crime themselves, McDonnell said. After committing a crime, people can be worried about their actions or proud about what they did, McDonnell said -- and often they share those feelings, either with friends or on social media.
"And we hope in this case that somebody does step forward, have the courage to do that -- make a call and hold people accountable," McDonnell said.
The three suspects were wearing dark clothes and driving a dark sedan, police said. The LAPD urges anyone with information to call 213-996-4142. Anonymous tips can be submitted to LA Regional Crime Stoppers at 1-800-222-TIPS.
ABC News' Jason Nathanson contributed to this report.