From 1993 to 1996, while an assistant United States attorney for the Southern District of New York, Andrew led the prosecution against the jihad organization of Sheik Omar Abdel Rahman. Following the September 11 attacks, Mr. McCarthy supervised the U.S. attorney's Anti-Terrorism Command Post in New York City, coordinating investigative and preventive efforts with numerous federal and state law enforcement and intelligence agencies.

He is currently a senior fellow at the Foundation for Defense of Democracies, serving as the director of the FDD's Center for Law and Counterterrorism.