John Martorano


Already the center of controversy in pre-trial arguments, the one-time feared hitman will be one of the government's star witnesses against the former Southie crime boss.

John Martorano cooperated with the government in exchange for a seven-year prison sentence for his crimes, a pretty light stint considering he admitted to 20 murders.

Expect the defense to attack his credibility, especially in light of reports that he continued to commit crimes after his release, a claim the government denies.