I write critically about criminal informants, but it bears remembering how they enabled the FBI to break the mafia. In June, mob boss “Cadillac Frank” Salemme was convicted of ordering the murder of a witness. Key witnesses against Salemme included Stephen “Rifleman” Flemmi, infamous killer informant in his own right who avoided the death penalty by testifying against Salemme and others. Salemme himself had been living under federal witness protection for having testified for the government over a decade ago. As one lawyer commented about the old mafia leadership, “Everybody’s been burned to a crisp here by informants.”
Whether it’s good public policy to cut deals with murderers in order to go after other murderers is a subject of long debate. At least some in Congress didn’t think so–see this report: Everything Secret Degenerates: the FBI’s Use of Murderers as Informants. It is now a violation of Department of Justice guidelines for the FBI to permit one of its informants to commit a violent crime, but violent criminals get leniency all the time in exchange for cooperation.