Beyond being Johnny's friend, Mark's background receives no exposition; when he is first introduced he claims to be "very busy" while sitting in a parked car in the middle of the day, with no explanation ever given as to his occupation or what he was doing. In "The Disaster Artist", Sestero states that he created a backstory for the character in which Mark was an undercover vice detective, which Sestero felt united several otherwise disparate aspects of Mark's character, including the secretive nature of various aspects of his behavior – including marijuana use – his mood swings, and his handling of the Chris-R incident. Wiseau dismissed adding any reference to Mark's past to the script. The makers of "The Room" video game would later introduce a similar idea as part of a subplot involving Mark's unexplained backstory, much to Sestero's amusement.