A federal grand jury indicted Class (D), for possessing firearms in his locked jeep, which was parked in a lot on the grounds of the United States Capitol in Washington, D. C. Statute 40 U. S. C. §5104(e)(1) states that “An individual . . . may not carry . . . on the Grounds or in any of the Capitol Buildings a firearm.” D appeared pro se and asked the Federal District Court for the District of Columbia to dismiss the indictment. D alleged that the statute, §5104(e), violates the Second Amendment. D also raised a due process claim, arguing that he was denied fair notice that weapons were banned in the parking lot. The District Court denied both claims. D pleaded guilty to “Possession of a Firearm on U. S. Capitol Grounds, in violation of 40 U. S. C. §5104(e).” As part of his written plea agreement set forth the terms of D's guilty plea, including several categories of rights that D expressly agreed to waive. Those express waivers included: (1) all defenses based upon the statute of limitations; (2) several specified trial rights; (3) the right to appeal a sentence at or below the judicially determined, maximum sentencing guideline range; (4) most collateral attacks on the conviction and sentence; and (5) various rights to request or receive information concerning the investigation and prosecution of his criminal case. The plea agreement expressly enumerated categories of claims that D could raise on appeal, including claims based upon (1) newly discovered evidence; (2) ineffective assistance of counsel; and (3) certain statutes providing for sentence reductions. The agreement contained an integration clause. The agreement said nothing about the right to raise on direct appeal a claim that the statute of conviction was unconstitutional. The District Court accepted D's guilty plea. D was sentenced to 24 days imprisonment followed by 12 months of supervised release. D appealed his conviction to the Court of Appeals. The Court of Appeals held that D could not raise his constitutional claims because, by pleading guilty, he had waived them. The Supreme Court granted certiorari.