At the end of February, a 300-page report, tersely titled, “New York Systemic Corruption,” was received for review by the Justice Department’s Office of the Inspector General in Washington. In three bound volumes, it detailed a series of oft-made, and explosive, allegations: that in the 1990s, while trying to stem the Colombo family war, federal prosecutors and agents for the Federal Bureau of Investigation in New York knowingly allowed two moles in the mob to kill while they were on the government’s payroll.