I’ve been getting a lot of questions lately about the Luigi Mangione case, and one question keeps coming up: How can someone potentially face both state and federal prosecution arising out of the same alleged killing? Doesn’t the Constitution prohibit double jeopardy?
It sounds like it should. But under longstanding Supreme Court precedent, the answer is more complicated.
The key is something called the dual sovereignty doctrine.
The Fifth Amendment says that no person shall “be subject for the same offence to be twice put in jeopardy of life or limb.” Most of us understand that as the government doesn’t get to prosecute you over and over again for the same crime.
And generally, that’s right.
But the Supreme Court has long held that the federal government and the individual states are separate sovereigns. Each derives its authority from a different source and each has its own laws to enforce.
That distinction matters enormously in the Mangione case.
Under the dual sovereignty doctrine, when the same alleged conduct violates both state and federal law, the Constitution does not necessarily treat those prosecutions as being for the same “offence.” Instead, the law views them as separate offenses against two separate sovereigns.
In other words, New York can prosecute an alleged violation of New York law, while the federal government can separately prosecute an alleged violation of federal law arising from the same underlying conduct.
That isn’t considered unconstitutional double jeopardy.
The Supreme Court reaffirmed this principle as recently as 2019 in Gamble v. United States. In that case, the Court rejected an invitation to overturn the dual sovereignty doctrine and reaffirmed the principle that an “offence” is defined by the law that creates it. Because state and federal governments enact their laws independently, violations of those laws can constitute separate offenses for purposes of the Double Jeopardy Clause.
The doctrine isn’t limited to state-versus-federal prosecutions, either.
In certain circumstances, two different states may prosecute conduct implicating the laws of both jurisdictions. Tribal sovereignty can also produce circumstances in which successive prosecutions are constitutionally permissible.
The underlying theory is fairly straightforward: each sovereign has an independent interest in enforcing its own laws.
Think about a criminal act that violates New York law but also interferes with an area specifically regulated by Congress. New York has an interest in enforcing its criminal laws and protecting people within its jurisdiction. The United States may have a separate federal interest established by Congress.
One prosecution does not automatically extinguish the other’s authority.
And that brings us back to Luigi Mangione.
There has been understandable confusion surrounding the fact that Mangione faces separate state and federal proceedings connected to the December 2024 killing of UnitedHealthcare CEO Brian Thompson. People naturally look at that and ask: How can the government prosecute someone twice for essentially the same alleged conduct?
The constitutional answer is that we’re not talking about one government prosecuting someone twice.
We’re talking about two sovereign governments exercising separate prosecutorial authority.
Now, whether prosecutors should pursue overlapping cases is a different question from whether they constitutionally can. There are Justice Department policies and practical considerations surrounding successive prosecutions, and defendants can certainly challenge particular charges or procedures on other constitutional and statutory grounds.
But the Double Jeopardy Clause, standing alone, does not create an automatic barrier simply because a state prosecution and federal prosecution arise from the same underlying event.
That distinction is important because the Mangione case has generated an enormous amount of commentary—some of it suggesting that whichever government gets to a verdict first automatically prevents the other from continuing.
That’s not how the dual sovereignty doctrine works.
A New York prosecution does not, simply by occurring first, automatically eliminate federal prosecutorial authority. Nor does a federal prosecution automatically erase New York’s authority to enforce its own criminal laws.
You can certainly debate whether having two governments prosecute substantially the same conduct is fair, efficient or necessary. In fact, the dual sovereignty doctrine has been criticized for precisely that reason.
But as the law stands today, the constitutional rule is well established.
Double jeopardy generally prevents the same sovereign from putting someone in jeopardy twice for the same offense. It does not categorically prevent two separate sovereigns from prosecuting violations of their respective laws arising from the same conduct.
And that is the legal principle to keep in mind as the separate proceedings involving Luigi Mangione continue to unfold.
The Valley Viewpoint 