Roscoe Sweeney, or "the Fixer", was a crooked fight promoter who was famous for tricking in boxing matches, extortion and gambling. He won lots of money doing this, and became a influental figure in the criminal scene in New York.
The Fixer (Roscoe Sweeney) was creatred by Stan Lee and Jack Kirby and first appeared in Daredevil Vol.1 issue 1 (1964).
Major Story Arcs
Roscoe tried to corrupt Jack Murdock with some money to lose. But Jack was determined to see his son happy and won. His best man, Slade killed Jack under Fixer's orders and forced Jack's son to grow up becoming DD. After many years DD finds both men and Fixer suffers a fatal heart attack while Slade is arrested and executed.
Daredevil: The Movie (2003)
His story is exactly as in the comics but he's named Fallon instead and Slade is a young Wilson Fisk. He was portrayed by Mark Margolis.
Roscoe Sweeney appears in flashbacks, portrayed by Kevin Nagle. In the series, he once again is shown as a gangster who fixes boxing matches. He sets up a fight between Jack Murdock and a young Carl Creel, with Jack set up to take a dive. Like in the comics, Jack instead chooses to win, which results in Sweeney having him killed.