Known for appearing in the FX series Sons of Anarchy, actor Paul John Vasquez died Monday in San Jose, California, from unknown causes. He was 48.

According to multiple reports, Vasquez was found dead at his father’s home. His father found him unconscious and called the paramedics. He was unable to be revived. The cause of death is being investigated.

He was born and raised in San Jose. After graduating in 1988, he moved to Los Angeles where he went on to pursue a career in acting.

In addition to portraying the character of Angel Ganz in two episodes of Sons of Anarchy, Vasquez appeared in numerous TV series including ER, CSI: NY, NYPD Blue, Justified, and How I Met Your Mother. Prior to that, his credits include various classic TV shows such as Simon & Simon and 21 Jump Street. He is also credited as a producer of the documentary Quincy Coleman: It’s All in the Song.

Vasquez was set to star in the short Thug Alley as well as Spody Gets His Gunz, two projects which he wrote. He was also set to star in the action thriller Lone Wolf.

His death comes after the death of fellow Sons of Anarchy actor Alan O’Neill. His body was discovered by his girlfriend in her apartment in June.