Consigliere to Carmine Lupertazzi for 30 years before his incarceration. Angelo was imprisoned on charges relating to a construction project in Yonkers. During his prison time, he became close friends with Tony Blundetto. He was released alongside Blundetto as part of the "Class of 2004".
Infighting occurred amongst the members of the Lupertazzi crime family following Carmine's death. Angelo chose Little Carmine's side along with capo Rusty Millio. Even though Angelo claimed to be "retired", he remained an important figure, and was suggested by Tony Soprano as part of a power sharing triumvirate to end the infighting. (Tony's proposal was that Johnny Sack, Little Carmine, and Angelo would all be equally in charge, but no major decisions could be made without a majority vote.) Angelo reluctantly went along with the idea. Interestingly though, Tony told Johnny Sack that the power sharing idea was Angelo's—this was intentional on Tony's part in order to allow him to maintain some distance from the conflict and appear merely as a neutral go-between, rather than a mediator (Tony had mentioned to Christopher Moltisanti that the instability between John and Little Carmine was serious.) Johnny Sack angrily dismissed this power sharing idea.
During the infighting, Angelo recruited his old friend, Tony Blundetto, to murder Joseph "Joey Peeps" Peparelli—an associate of Johnny Sack and member of Phil Leotardo's crew. Following this, Phil and his brother, Billy Leotardo, killed Angelo.
Angelo's murder had two major repercussions—it caused Little Carmine to withdraw from the fight, as he couldn't stomach any more bloodshed, making Johnny Sack the undisputed successor to Carmine, Sr. It also provoked Tony Blundetto to pursue the Leotardos, shooting and killing Billy Leotardo while wounding Phil. This nearly started a war between the New York and New Jersey crews, and anger from this conflict remained until The Sopranos' conclusion.