Armus' Hollywood career began when, while he was still serving as an NYPD detective assigned to the 48th Squad in the Bronx, he was hired to be the technical advisor on the TV series N.Y.P.D.
Later, still a serving detective, he was picked by Telly Savalas to act as a technical adviser on the Kojak series.
Following his retirement from the police department he moved to Los Angeles and became a successful writer and producer.
Director Richard Donner, who directed three episodes of Kojak, named a detective in his blockbuster film Superman after Armus.
In 1994, Armus won a Humanitas Prize for 60 Minute Category (NYPD Blue; 1993), which was shared with David Milch.