RALEIGH, N.C., Dec. 26 (UPI) -- Frank Calabrese Sr., a convicted Chicago mob hit man, died on Christmas Day at the age of 75 in a North Carolina federal prison, an official said.
Calabrese and two other mobsters, Joseph "Joey the Clown" Lombardo and James Marcello, were found guilty of 10 murders during the 2007 Operation Family Secrets trial, the Chicago Tribune reported Wednesday.
A Federal Bureau of Prisons spokesman said Calabrese died at the Butner Federal Correctional Complex, where he had been serving a life sentence.
The Operation Family Secrets trial was a large organized crime case in Chicago, in which Calabrese and the other defendants were convicted of racketeering. They allegedly extorted "street tax" from businesses, were involved in loan sharking and ran illicit sports and poker operations. They allegedly killed people they thought would turn state's evidence or already had done so.
Until the Operation Family Secrets trial, the cases were unsolved for decades, the Tribune said.