Lt. Percy Bacharach works for the Chicago Police Department, and has made it his personal mission to have Bean thrown in jail for his activities, namely because of Bean's courier business that's having a lot of police cruisers wrecked pursuing him. During the Grimwood kidnapping case which Bean and Rally were framed as the kidnappers, he was able to obtain a tool that might finally get the job done – a 1967 Ford Mustang Shelby Cobra G.T. 500 (that same car was also Rally's car in 'Gunsmith Cats'), close to a match for Bean's custom Ford RS-200, a.k.a. 'The Buff'.
Percy's obsession with his rival is maniacal, and he will stop at nothing to take down the Road Buster. As we see in Gunsmith Cats BURST, he'll pull no stops in his quest, from hiring terrorists to protecting mafia kingpins to blackmailing his chief in order to continue his illegal methods. He'll even work with Bean if it means he's garaunteed a shot at the Road Buster in the future.
Strangely, just like Bean himself, Percy prefers to use American muscle cars for his work, claiming that doing so makes him feel like "an American hero". Because of this shared fondness for road racing these old cars, Percy and Bean are able to negotiate using the promise of a one on one race to settle their score. Despite their shared animosity towards each other, there's a level of respect, as both adhere to their guarantees to each other no matter what.
Percy is introduced early on in BURST, appearing identical to his Riding Bean appearance, as well as sporting an obsession with defeating Bean Bandit. He original hails from Detroit, which was a common stop for Bean during many of his missions, so much so that Bean would frequently destroy multiple police cruisers during his visits. This planted the seeds of Percy's obsession, and he transfers to Chicago after his investigation indicates that Bean was headquartered in the greater Chicago area.
During Gunsmith Cats BURST, Bean is eventually arrested by Percy, but Percy frees him, coming to an understanding with the Road Buster in the process. The two arch rivals agree to settle their differences on the road in a duel to the death. In preparation, Percy gains financial backing from a local crime lord recently decimated by Bean, buys a 1971 Ford Mustang Mach 1, and hires Middle Eastern terrorists armed with rocket launchers to ambush Bean during an illegal V8 road race. Percy's plan fails, though neither Bean nor Percy die in the process, and it is presumed that their rivalry continues even after Gunsmith Cats BURST concludes.