The police tactics used during the 2001 Quebec City protest serve as an example of the approaches used by North American riot police . During the protest , riot police fired tear gas canisters , water cannon , and rubber bullets , dispersing large groupings of protesters both violent and peaceful , including teach-ins and teams of medics providing first aid to other protesters . Other tactical interventions aimed at arresting various perceived movement leaders . Allegedly , " plastic bullets were being used increasingly by riot police , and from guns with laser sights so at night people could often see that the cops were intentionally aiming for heads or groins . " Some U.S. SWAT teams have adopted the AR-15 carbine . Some U.S. police departments are using the M4 carbine , which will replace the M16 as the main U.S. Army combat assault rifle . " After the North Hollywood shootout in 1997 , the Department of Defense gave 600 surplus M16 assault rifles to LAPD , which were issued to each patrol sergeant . Various U.S. SWAT teams are armed with the Heckler & Koch MP5 , a submachine gun
North Hollywood shootout
North Hollywood shootout
Militarization of police