Mangione still faces murder charges in a state trial set to begin next month, but his guilty plea in federal court is expected to have significant impacts on the state trial. New York state's strict double jeopardy law could potentially upend those proceedings. That law says that a defendant can't be tried twice for the same thing.
That's some 4D chess from the defense there. Plead guilty to a federal stalking charge so New York state can't charge you with second degree murder. We'll see if that works out as planned.