The militarization of police (paramilitarization of police in some media) is the use of military equipment and tactics by law enforcement officers. This includes the use of armored personnel carriers (APCs), assault rifles, submachine guns, flashbang grenades, sniper rifles, and SWAT (special weapons and tactics) teams. The militarization of law enforcement is also associated with intelligence agencyβstyle information gathering aimed at the public and political activists and with a more aggressive style of law enforcement. Criminal justice professor Peter Kraska has defined militarization of police as "the process whereby civilian police increasingly draw from, and pattern themselves around, the tenets of militarism and the military model".
Observers have noted the militarizing of the policing of protests. Since the 1970s, riot police have fired at protesters using guns with rubber bullets or plastic bullets. Tear gas, which was developed by the United States Army for riot control in 1919, is still widely used against protesters. The use of tear gas in warfare is prohibited by various international treaties that most states have signed; however, its law enforcement or military use for domestic or non-combat situations is permitted.