Batty's brain was malformed, containing calcium deposits in the left and right amygdala, causing him to have no sense of fear. He was a military combat specialist who did tours in Schweinfurt, Provo, Novaya Zemlya, and Caracas. He also worked as a mercenary, hired by the United Nations and the Tyrell Corporation as Eldon Tyrell's bodyguard. The organization used him as a templant for a line of replicants bearing his name.
In 2020, after being hired by Sarah Tyrell – under the guise of the Los Angeles Police Department – to hunt down the sixth replicant, Batty broke into a hospital and retrieved wounded Blade Runner Dave Holden, who had been shot by the replicant Leon Kowalski the previous year.
He had Holden fitted with an artificial heart and lungs and informed him of his belief that Holden's shooting at the hands of Leon had been a setup orchestrated by Harry Bryant. Additionally, Batty told him that he believed all Blade Runners were actually replicants.
Believing Rick Deckard to be the sixth replicant, Batty set out to find him, accompanied by Holden, who insisted they go to Deckard's old apartment. In the apartment, Holden managed to attack Batty and handcuff him to a toilet pipe in the bathroom.
Batty managed to free himself through the use of nearby dental floss and a razor blade. Holden soon returned to the apartment and Batty attacked him, letting him go when he offered the identity of the sixth replicant, now agreeing that it was Deckard.
They waited at a Blade Runner safehouse for Deckard's arrival and attacked them. However, Deckard managed to escape from them and Batty gave chase after a brief scuffle with Holden, shooting him in the shoulder and leaving him behind. Batty managed to catch up to Deckard on a section of freeway. The two fought, Deckard suspecting that Batty was the sixth replicant. Batty soon gained the upper hand and prepared to kill Deckard, but was shot in the head by Holden.