Wactor was shot and killed in downtown Los Angeles early Saturday morning, his mother Scarlett tells TMZ. She says Johnny was with a coworker when they saw three men messing with Johnny's car. While authorities haven't released his name, this matches the description of an incident where three suspects allegedly tried to steal a catalytic converter.

Scarlett says she was told Johnny didn't try to fight or stop them ... but, the men shot him anyway before taking off. According to police info, paramedics rushed to the scene just after 3 AM PT. He was pronounced dead at the hospital.

Police have not provided a description of the suspects ... but, Johnny's mother says she hopes they'll be found quickly.

Johnny got his start in acting back in 2007 on the hit Lifetime show "Army Wives," playing a few different roles before working steadily over the next two decades.

Some of his bigger credits include "Westworld," "The OA," "NCIS," "Station 19," "Criminal Minds," and "Hollywood Girl."

Many of Johnny's fans will remember him for his time on 'GH' where he played Brando Corbin -- married to drug addict Sasha Corbin in the series. He played the role from 2020 until his character was written off the program in 2022.

Wactor's mother remembers him as a loving young man ... adding his death leaves a huge hole in the family's heart.

He's survived by his mother, and his younger brothers Lance and Grant. He was 37.