A few years after retiring from his celebrating acting career, Law & Order: Special Victims Unit star Richard Belzer has died at the age of 78. Though having gotten his career started in the early '70s with his stand-up comedy, Belzer became best-known for portraying the Baltimore Homicide Detective-turned DA Investigator John Munch in Dick Wolf's interconnected crime drama universe. Starring first in Paul Attanasio's Homicide: Life on the Street, Munch would later return in the original Law & Order before acting as one of the main characters in Law & Order: Special Victims Unit right up until his retirement from acting in 2016.Deadline has brought word that Richard Belzer has died at the age of 78. At the time of reporting, it's unknown what the actor and comedian's cause of death was, with Saturday Night Live alum Laraine Newman having first announced his passing while representatives later confirmed. Multiple of Belzer's Law & Order: Special Victims Unit co-stars, including Christopher Meloni and Mariska Hargitay, subsequently took to social media to share their heartbreak for the news, which can be seen below: Related: Law & Order: SVU: Detective Munch’s 10 Best Moments From His Time On The Show

Richard Belzer's Hollywood Legacy Remembered

Richard Belzer as John Munch on Law & Order: SVU

After starting his career as a reporter and in the field of stand-up, Belzer would eventually make his way to the screen in the mid 1970s with minor appearances in Saturday Night Live, Sesame Street and Fame, among other things. Off-screen, Belzer was also finding his success in the world of radio with frequent appearances on the National Lampoon Radio Hour, in which he starred alongside comedy icons John Belushi, Chevy Chase, Bill Murray, Gilda Radner, and Harold Ramis.

Belzer's big claim to fame would come in 1993 with Homicide: Life on the Street, in which he played the cynical and conspiracy theory-obsessed John Munch. Following that show's cancelation, as well as such crossover appearances in Law & Order and The X-Files, Munch would become a main character in Law & Order: Special Victims Unit, appearing in a regular role from season 1-15. Though latter season saw Munch put in for his retirement, he would still return for a handful of guest appearances in the years that followed.

While already a big feat to play a character for over 400 episodes across two shows, Belzer has an even more unique record to his name as Law & Order: Special Victims Unit's Munch is the only fictional character played by a single actor to appear on 11 different shows. Outside of the NBC crime shows, Belzer also reprised his beloved character in The X-Files, The Beat, Arrested Development, The Wire, 30 Rock and Unbreakable Kimmy Schmidt. Audiences can look back and honor Belzer's legacy with all 24 seasons of Law & Order: Special Victims Unit streaming on Peacock.

More: Law & Order: SVU — 10 Things You Missed About John MunchSource: Deadline