[citation needed] One of Mohr's early starring roles on radio was as a replacement for Matt Crowley for a brief interval in Jungle Jim in 1938.

[2]: 205 He was one of the actors who portrayed Archie Goodwin in The New Adventures of Nero Wolfe,[3] frequently starred in The Whistler, and acted in different roles in multiple episodes of Damon Runyon Theater and Frontier Town.

After three years' service in the US Army Air Forces during World War II, he returned to Hollywood, starring as Michael Lanyard in three movies of The Lone Wolf series in 1946–47.

In 1949, he was co-announcer, along with Fred Foy, and narrator of 16 of the shows of the first season of The Lone Ranger, speaking the well-known introduction as well as story details.

He also appeared in the Maverick episodes "You Can't Beat the Percentage", "The Burning Sky", "Mano Nera" and "The Deadly Image".

He also essayed Captain Vadim, an Iron Curtain submarine commander, in the Voyage to the Bottom of the Sea episode "The Lost Bomb".

In the series' fourth and final season (1968-69), Mohr guest-starred in the episode "Flight From San Miguel" on The Big Valley with Barbara Stanwyck.

He played "Ricky's friend", psychiatrist "Dr. Henry Molin" (real life name of the assistant film editor on the show), in the February 2, 1953 episode of I Love Lucy, "The Inferiority Complex".

Mohr flew to Stockholm in September 1968, to star in the pilot of a proposed television series, Private Entrance, featuring Swedish actress Christina Schollin.

[citation needed] Shortly after the completion of filming, Mohr died of a heart attack in the evening of November 9, 1968, in Södermalm, Stockholm, aged 54.