Preventing and responding to domestic terrorist attacks requires that State and local law enforcement agencies collaborate across jurisdictional boundaries in ways unimagined 20 years ago. Sharing intelligence and investigating possible leads require that States and Federal law enforcement officials establish agreements and common systems for exchanging information. Currently, a wide range of new and revised compacts address various facets of public safety and criminal justice, including the transfer of prisoners, criminal history repositories, drug enforcement, drivers' safety and licenses, and civil defense and emergency management; however, collaboration among State and local law enforcement agencies will likely increase in importance as new security threats emerge, people become more mobile, and technology continues to blur jurisdictional lines. Policymakers and law enforcement officials should consider forming multijurisdictional regions through agreements. Regional efforts provide opportunities for State and local jurisdictions to do more with less. They should also examine the establishment of professional standards for terrorism prevention, as well as develop and share mutual aid procedures for law enforcement. Although interstate and intrastate mutual aid mechanisms currently exist, they lack resource-sharing procedures and plans for State and local law enforcement practitioners. Further, quantitative and qualitative methods should be used to evaluate the adequacy of new State laws and interjurisdictional agreements. 37 notes