The report first describes assault weapons as "semiautomatic firearms designed with military features to allow rapid and accurate spray firing." Assault weapons are designed to perform the military function of killing large numbers of people by making spray firing easy. Twenty percent of the law enforcement officers killed in the line of duty from 1998 to 2001 were killed with an assault weapon. This report advocates banning assault weapons because their only function is to kill humans quickly and efficiently. A brief history of assault weapon regulation in the United States is presented, followed by an assessment of the adequacy of the Federal assault weapon ban. This assessment advises that renewal of the Federal assault weapon ban is essential, but it should be strengthened to remove its numerous loopholes. Existing State and local assault weapon bans are reviewed, and the rationale for State and local action in instituting such bans is developed. Seven appendixes address the following topics: assault weapon laws in the United States, a comparison of Federal and State assault weapon bans, profiles of Federal and State assault weapon bans and litigation, common legal challenges to laws that ban assault weapons, excerpts of the Federal assault weapon ban, excerpts of the California assault weapon ban, and a model law to ban assault weapons composed by the Legal Community Against Violence.