John Zderko has tragically lost his battle with cancer.
The Criminal Minds actor has died at the age of 60 following complications from his treatment.
His friend and fellow actor Charlie Koontz shared the devastating news on social media after breaking it to the Hollywood Reporter on Thursday.
He tweeted: "A great friend and an excellent actor gone way too soon.
"Thank you so much to @THR and @MikeBarnes4 for giving our friend a true Hollywood sendoff.
"And to @captainblackusa for the great idea. Your name in lights one more time, John. Love you pal. RIP."
John has left behind his sister Karen and nephews Jason and Jeff.
The beloved actor made his first screen appearance in 2005 and went on to appear in 9-1-1: Lone Star, Dirty John and The Player. John has also starred in The Mentalist.
His most recent roles were in Bleeker Street's Breaking, which debuted at the Sundance Film Festival, and in Bosch: Legacy.
John grew up in Ohio, Colorado and New Jersey.
He graduated from UC Irvine and started taking acting classes at UCLA.
The star started out on stage in Santa Monica at the West of Broadway after quitting his full-time job to pursue acting.
Over on social media, people paid their respects to the star as they heard about the news.
One wrote: "Memories live on. sending my sympathy to you and all who will miss him."
Another penned: "Whaaa? Ugh I’m crestfallen reading this. Great guy. He will be missed."
