Major Story Arcs
In the first issue of Year One, Flass is seen hurting someone trying to sell books at the train station and beating up a teenage boy. After Jim Gordon refuses to take a bribe, Flass and other corrupt policemen attack Jim in a parking lot with bats, injuring him enough to leave visible marks, but not enough to send him to the hospital. Later, after a night of drinking and playing poker with other cops, Flass is rammed off the road by Gordon and beaten. Just as Flass and the cops did to Gordon, he roughed him up just enough so he wouldn't have to go to the hospital. Gordon stripped Flass, handcuffed him, and left him by the side of the road knowing that Flass would never admit that he was attacked by Gordon.
In the second issue Flass is attacked by Batman, while in the middle of a cocaine delivery. Flass tells the story to Gordon and other members of the police force but, makes it sound like he was there to bust the gang members. No one believes him, but no one challenges his story though, while telling the story Flass gets embarrassed.
In the last issues Batman takes down a drug dealer named Jefferson Skeevers and makes him turn himself in and reveal that Flass is a part of Gotham's drug operation. After spending two weeks in jail, Flass revealed that he had notes on every time he had a meeting with Commissioner Loeb causing Loeb to turn in his resignation.
Following his arrest, Flass took a job as the bouncer at the Leopard Room. However, he was killed by the Hangman, while on a smoke break.
Detective Flass appears in the live action Batman Begins, where he is once again highly corrupt and Jim Gordon's partner, played by Mark Boone Junior. He would frequently work protection for Carmine Falcone, leading to his confrontation with Gotham's vigilante, the Batman. He was later brought under the effect of the Scarecrow's fear gas and almost murdered several innocents, but was knocked out and detained by his partner Jim Gordon.
Mark Boone Junior reprises his role for the video game adaptation, where he can be seen conducting an interrogation on Mr. Zsasz.
Flass, played by Dash Mihok, makes his debut in the 12th episode "What the Little Bird Told Him" where he can be seen interrupting Edward Nygma's latest attempt at flirting with Kirstin Kringle in the GCPD offices. Gordon later goes after Flass when he finds out his involvement in a murder case, but finds himself battling the corrupt GCPD hierarchy as a result.
Batman: Year One
Flass appears in the Year One animated adaption, Batman: Year One. During the movie he filled much the same role as he did in the original story line.