Anxious FBI chiefs are trawling through 'numerous' top-level investigations spanning 22 years for fear they were compromised by convicted bureau spook Charles McGonigal, DailyMail.com can reveal. The forensic clean-up operation ranges over the entire time the philandering former head of counterintelligence in New York worked for the agency. McGonigal, 55, has already been sentenced to four years and two months in prison for taking money and conspiring with a sanctioned Russian oligarch who is a crony of despot President Vladimir Putin. But the full possible repercussions of his treachery are outlined in a sentencing memorandum by the US government for...