After mobster Anthony "The Hatch" Chiaramonti was gunned down in 2001, law enforcement sources privately pointed to Anthony Calabrese as the triggerman.
But the feds went public with the allegation in a little noticed document filed last year in Calabrese's trial on three separate armed robbery charges.
In that document, the feds talk about the background of several of the witnesses who will testify that they committed the robberies with Calabrese.
The feds said they aren't going to bring up the murder allegation Calabrese. He has never been charged in the case.
But one of the witnesses at the upcoming armed robbery trial "committed a murder in 2001 with defendant Calabrese for which the witness pleaded guilty in Cook County Circuit Court," the court filing reads.
"The actual shooter was defendant Calabrese and the person shot was Anthony Chiaramonti," the filing reads.
The witness the document refers to is Robert Cooper, who pleaded guilty in Chiaramonti's murder and was sentenced to more than 20 years in prison.