Ron Glass, Star of 'Barney Miller' and 'Firefly,' Dead at Age 71

— -- Ron Glass, the actor best-known for his role on the 1970s sitcom "Barney Miller" and the sci-fi series "Firefly," has died at age 71.

In a statement to ABC News, Glass' agent, Jeffrey Leavitt, confirms Glass died Friday night of respiratory failure.

"Ron was a private, gentle and caring man. He was an absolute delight to watch on screen," Leavitt said. "Words cannot adequately express my sorrow."

Born in Indiana, Glass appeared in supporting roles in a number of 1970s TV series before landing his breakout role as the dapper, erudite police Det. Ron Harris on "Barney Miller." He played the character for the show's entire eight-season run, earning an Emmy nomination for the show's final season in 1982.

In 2002, Glass found a new generation of fans playing Shepherd Darriel Book, a preacher traveling with a crew of smugglers in outer space, on the Joss Whedon-created short-lived cult TV series "Firefly." He reprised the role in the spin-off film "Serenity" three years later.

"Castle" star Nathan Fillion, who also starred with Glass in "Firefly," posted a photo on Instagram of Glass with a quote from the show, ending with, "We love you, Ron Glass. Don't go far." Joss Whedon tweeted that Glass had "grace, humor & enormous heart," adding, "He was, among so many other things, my Shepherd."

Off-screen, Glass was a practicing Buddhist.