Maginty grew up in Dublin, before moving to New York as a young man. Like many criminals in Hell's Kitchen, Maginty was affiliated with Nesbitt, but was often bullied and insulted for his race by the elderly gangster, who used to throw peanuts at him and refer to him as "Paddy the Monkey". Maginty would eventually go on to start his own gang, which consisted of African-Americans. When Nesbitt died, Maginty received a letter with a piece of code, informing him that he needs to work with the other gang leaders in Hell's Kitchen if they want to get Nesbitt's inheritance of $10 million.
Wanting to keep all the money for himself, Maginty had Tommy Toner, the leader of the Westies, kidnapped. He then forced Napper French to cut Tommy up piece-by-piece while keeping him alive. He would then mail the pieces to the Westies in an attempt to scare them and perhaps get their piece of the code. In a cruel prank, Tommy took Napper's grandson into the torture chamber and showed him his grandfather's work, horrifying the boy. Maginty then requested Napper cut off one final piece off Tommy.
Maginty then requested to meet with Brenda Toner, Tommy's wife and now leader of the Westies. When he and his gang arrived, the Westies were already being massacred by the Punisher. Maginty snuck up on the Punisher, but the latter noticed him and his gang in the last second, and killed most of them, though Maginty was able to escape. Before he left, Maginty gave Brenda Tommy's head. When he got back to his apartment, Maginty was knocked out by Napper French and tied up. Napper wished to eviscerate Maginty alive, in a similar manner to Tommy Toner, as revenge for traumatizing his grandson. Napper only succeed in cutting off Maginty's fingers on his left hand however, before he was discovered and killed by Maginty's men.
Maginty then met with the other gang leaders and finally agreed to a truce. They tracked the cash down to an abandoned ship, but came under attack from the Punisher. The leaders were able to the prize, but when they opened it, they discovered that the briefcase Nesbitt left was in fact a bomb, with "CUNTS" engraved on it as a final insult. Maginty was killed in the explosion, along with the other gang leaders.