Chicago mobster Frank Calabrese Sr., a known hit man who strangled victims and slit throats, died earlier this week in a federal prison at the age of 75.
Calabrese passed away Tuesday at the Butner Federal Medical Center, said Ed Ross, a spokesman for the North Carolina Federal Bureau of Prisons.
Ross had no information on the cause of death, though Calabrese claimed in 2009 to be suffering from a host of ailments, including an enlarged heart.
"It's very emotional right now because there were two sides to my dad, and I miss the good side," son Frank Calabrese Jr. told the Chicago Sun-Times.
The younger Calabrese isn't kidding about his mixed emotions; he actually helped put his father away by secretly recording him boasting about mob killings.