Luigi Mangione's Defense Says State, Federal Prosecutors Using Him as a 'Pawn'

Luigi Mangione's lawyers are asking the judge in his state case to toss it out on double jeopardy grounds, now that he's pleaded guilty in his federal case ... and they say prosecutors are using him as a "pawn" in a sick game.

In court docs, obtained by TMZ, Mangione's lawyers are asking a judge to dismiss the eight charges still pending in his state case -- second-degree murder and seven weapons charges -- stemming from the December 2024 killing of UnitedHealthcare CEO Brian Thompson.

Mangione's defense argues his federal guilty pleas now bar the state case from moving forward under the federal Constitution and New York's double jeopardy law ... while accusing state and federal prosecutors of using him as a "pawn" in a coordinated push to punish him twice.

His lawyers claim Mangione's Fifth Amendment due process rights were violated because the Manhattan District Attorney's Office and Justice Department essentially coordinated the two prosecutions to punish him twice for the same offense -- killing Thompson.

Mangione's attorneys say he has been a "pawn" from the start as the two offices battled over which case would go first ... claiming prosecutors eventually worked together to ensure both sides got a shot at prosecuting him.

The defense claims the coordinated plan was specifically designed to allow two successive prosecutions ... accusing the state and federal governments of trying to "maximize his punishment" and increase their respective chances of convicting Mangione.

As we reported ... Mangione's lawyers announced their plans to seek dismissal following his guilty plea Friday ... and the newly filed paperwork now lays out their argument in detail.

Mangione pleaded guilty in federal court earlier today to two stalking charges stemming from the December 2024 killing of Thompson.

When Mangione is sentenced in December, U.S. Attorney Jamie McDonald says his office intends to seek life in prison.