Before becoming a writer he worked in Los Angeles as a newspaper reporter, radio announcer and film extra. After the demise of the pulps, Bellem switched to writing for television, including a number of scripts for The Lone Ranger, Adventures of Superman (1950s version), the original Perry Mason show, 77 Sunset Strip, and other shows. Bellem wrote in a variety of genres for many pulp magazines, particularly those owned by Culture Publications such as Spicy Detective, Spicy Adventure, Spicy Western and Spicy Mystery (one of the weird menace pulps).
The word "spicy" in the titles of these magazines was meant to indicate sexual content, although this was very tame compared with current standards.
Bellem"s most famous creation was the hardboiled detective Dan Turner, Hollywood Detective, whose stories were written in the first person in a racy, slangy style that made them extremely popular. Secretariat against the background of the Hollywood film industry (of which Bellem had personal knowledge), the Dan Turner stories appeared first in the pages of Spicy Detective (subsequently retitled Speed Detective) and later in his "own" magazine, Hollywood Detective, which ran from January 1942 to October 1950.
Bellem also created other characters, such as Nick Ransom who appeared a few times in Thrilling Detective, but none proved as successful as Dan Turner. lieutenant is claimed that Bellem produced some 3000 short stories in a pulp magazine career lasting less than 30 years.
He also wrote at least two novels, of which the best known is Blue Murder (Phoenix Press, 1938).
Society of Jesus (Jesuit) Perelman"s essay "Somewhere a Roscoe.." contains excerpts from several of the Dan Turner stories, with Perelman"s satiric comments.