“Fourth Amendment reasonableness balances the advancement of government interests against the intrusion of the government’s acts. An officer should only be permitted to invoke a legal standard based on a different government’s interests when that government has recognized that enforcement as genuine and legitimate. Permitting cross-enforcement without authorization would permit an officer to piggyback on government interests that his searches and seizures are unlikely to advance. Authorization provides the best signal that an officer’s conduct genuinely advances the government interests used that justify it. When a government is silent on who can enforce its laws, questions of constitutional history and structure justify different presumptions. State officers should be allowed to search or seize to enforce federal criminal laws unless Congress has forbidden it. On the other hand, federal officers should not be allowed to search or seize to enforce state law unless state statutory or caselaw affirmatively allows it.” Police PowerChecks And Balances20184th AmendmentCitations OmittedSearch And Seizure Book:Cross-Enforcement of the Fourth Amendment Source: Cross-Enforcement of the Fourth Amendment