If a crime occurs in two or more states, can each prosecute it?
Usually, any state in which an essential part of a crime has been committed can prosecute the offender. That means that authorities in each affected state can prosecute a crime that stretches from one territory to another. The double jeopardy prohibition doesn’t apply to separate “sovereigns,” meaning that this kind of multiple prosecution doesn’t run afoul of the Constitution. In fact, it’s at least theoretically possible that multiple states and the federal government could prosecute a defendant for a single course of conduct. (The federal government would derive jurisdiction, for example, by the fact that (1) the Constitution allows it to regulate interstate commerce and (2) the crime crossed state lines.)
Example: A man hired two men to kill his wife. Pursuant to his plan, the men kidnapped the wife in Alabama, then drove her into Georgia and killed her. The man pleaded guilty to murder in Georgia in exchange for a life sentence. After the plea, an Alabama court tried and convicted him and sentenced him to death. The U.S. Supreme court held that, under the dual sovereignty principle, two states may separately prosecute a defendant for the same conduct without violating the Fifth Amendment’s Double Jeopardy Clause. (Heath v. Alabama, 474 U.S. 82 (1985).)