Which amendment of the U.S. Constitution states the reserved police powers?

The correct answer is the 10th Amendment, which emphasizes the principle of federalism by stating that any powers not delegated to the federal government nor prohibited to the states are reserved for the states or the people. This means that unless the Constitution specifically grants powers to the federal government, those powers are retained by the states.

The police powers—those powers that allow states to enact laws to protect the health, safety, welfare, and morals of their citizens—are part of this reserved powers doctrine. As a result, the 10th Amendment provides the legal foundation for states to maintain police forces, enact criminal laws, and ensure public order, which highlights its significance in law enforcement context. Understanding this amendment is crucial when discussing the powers and responsibilities of state versus federal law enforcement agencies.