How does a District Attorney's office go about prosecuting a former U.S. president? Donald Trump makes for a tricky defendant under any circumstances, but factor in the unprecedented nature of the criminal trial getting underway today in New York focusing on America's former chief executive ... and things get downright complicated.

KNX chief correspondent Charles Feldman talked with Catherine Christian, who formally served as a prosecutor in the Manhattan D.A.'s office, asking whether her former colleagues were up to the task.