Observers have noted the militarizing of the policing of protests.[10][11] Since the 1970s, riot police have fired at protesters using guns with rubber bullets or plastic bullets.[12]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[13] that most states have signed; however, its law enforcement or military use for domestic or non-combat situations is permitted.
Concerns about the militarization of police have been raised by both ends of the political spectrum in the United States, with both the libertarian Cato Institute[14] and the American Civil Liberties Union (ACLU)[15] voicing criticisms of the practice. The Fraternal Order of Police has spoken out in favor of equipping law enforcement officers with military equipment, claiming that it increases the officers' safety and enables them to protect members of the public and other first responders (e.g., firefighters and emergency medical services personnel).[16] However, a 2017 study showed that police forces which received military equipment were more likely to have violent encounters with the public, regardless of local crime rates.[17] A 2018 study found that militarized police units in the United States were more frequently deployed to communities with large shares of African-Americans, even after controlling for local crime rates.[18]
Many countries also have at least one gendarmerie, which is a military force with law enforcement duties among the civilian population.
France classifies some weapons as "intermediary force weapons" such as its LBD 40 refitted version of the Swiss B&T GL06 military grenade launcher, which is used in riot police situations or against individual persons in more specific interventions.
While not having the full power of military guns, some weapons are heavier than regular police weaponry and are still lethal. These are often referred to with the "limited lethality" appellation.
^Texas Rangers, Department of Public Safety, Branch Davidian EvidenceArchived January 7, 2009, at the Wayback Machine, Investigative Report No. 1, September 1999; Investigative Report No. 2, January 2000 (PDFs available at Texas Rangers website). The Rangers found that the FBI used grenade launchers to fire two 40 mm M651 grenades. The Army considers the M651 a pyrotechnic device and that it is known to cause fires. The Army Tech Manual for the M651 warns that it can penetrate 3/4" plywood at 200 meters and "projectile may explode upon target impact". During inventory of the Waco evidence the Texas Rangers also found flashbang grenades.
^James Joyner (June 15, 2011). "Militarization of Police". Outside the Beltway. Archived from the original on December 21, 2015. Retrieved November 12, 2015.