What has the highest level of authority in criminal law?

Federal statutes hold the highest level of authority within the realm of criminal law because they are enacted by Congress and apply uniformly across the entire United States. This federal framework is essential for maintaining consistency in legal standards and enforcement across state lines, particularly in cases involving crimes that transcend local jurisdiction or require interstate collaboration, such as drug trafficking or human trafficking.

While state statutes are crucial and can vary widely from one state to another, they cannot contravene federal law due to the Supremacy Clause of the U.S. Constitution, which establishes that federal law prevails when there is a conflict. Local ordinances are even lower in the hierarchy, as they are specific to municipalities and can only address issues within their geographical boundaries. International treaties, on the other hand, while significant in some legal contexts, do not generally govern domestic criminal law except in specific areas where the U.S. has agreed to compliance.

Thus, federal statutes not only create a baseline for criminal law that all states must adhere to but also provide a framework for addressing criminal activity that has implications beyond local jurisdictions.