On May 18, 2007, the star witness in the government's case against 14 Chicago mob figures, Nicholas Calabrese, pleaded guilty to taking part in a conspiracy that included 18 murders, including the hits on Anthony and Michael Spilotro. Under heavy security, Calabrese admitted that he took part in planning or carrying out 14 of the murders, including the Spilotro killings. He became the key witness against his brother, Frank Calabrese, Sr., and other major mob figures charged in the government's Family Secrets Trial. Calabrese agreed to testify after the FBI showed him DNA evidence linking him to the murder of fellow hit-man John Fecarotta, who was also allegedly involved in the Spilotro slayings.