Charles McGonigal, former special agent in charge of the FBI's counterintelligence division in New York, arrives to Manhattan federal court in New York, Thursday, Feb. 9, 2023, in New York.John Minchillo/AP Charles McGonigal pleaded guilty on Tuesday to working with a sanctioned Russian oligarch. The former FBI agent was once a top counterintelligence chief. He admitted to money laundering and violating sanctions. Charles McGonigal, a disgraced former FBI agent, pleaded guilty on Tuesday to working with a sanctioned Russian oligarch.