His emotions were at a much lower level of development than Roy's, but he evidently believed in Roy's quest for more life. Leon was classified as mental level C. He did not have the speed of thought Roy had when it came to getting through a situation, resorting instead to simple violence.
Los Angeles Police Department Inspector Harry Bryant told Deckard that after the first unsuccessful attempt to infiltrate the Tyrell Corporation by replicants, the police assumed that the replicants might try again by disguising themselves as Tyrell employees. Therefore, they started to question all of the workers at Tyrell's Level 9 replication center. Leon, undercover as one of the employees, ended up being interviewed.
On the RunEdit
Blade Runner Dave Holden interviewed Leon, utilizing a Voight-Kampff machine. As Holden began to suspect Kowalski of being a renegade replicant, Leon brandished a gun and shot him. Leon escaped the Tyrell Corp. building and was left to roam the streets of Los Angeles freely.
Blade Runner Rick Deckard was called in to retire Leon after an encounter with Zhora. Leon spotted Deckard on the streets, following Rachael and decided to tail Deckard to surprise him and ultimately kill him.
Leon later beat Deckard severely after he witnessed him kill Zhora. Just as he was about to gouge his fingers through Deckard's eyes, he was shot by Rachael, who had picked up Deckard's gun.
Leon had cherished photographs of his friends. Unlike Rachael's false photos of her childhood, these were current photos of the only ones who mean something in his life.