The ineffectiveness of the standard police patrol pistols and shotguns in penetrating the robbers' body armor led to a trend in the United States (including cities such as Miami) toward arming selected police patrol officers, not just SWAT teams, with heavier firepower such as semi-automatic 5.56 mm AR-15 type rifles. SWAT teams, whose close quarters battle weaponry usually consisted of submachine guns that fired pistol cartridges such as the Heckler & Koch MP5, began supplementing them with AR-15-based assault rifles and carbines. Seven months after the incident, the Department of Defense gave 600 surplus M16s to the LAPD, which were issued to each patrol sergeant; LAPD patrol vehicles now carry AR-15s as standard issue, with bullet-resistant Kevlar plating in their doors as well. Also as a result of this incident LAPD authorized its officers to carry .45 ACP caliber semiautomatic pistols as duty sidearms, specifically the Smith and Wesson Models 4506 and 4566. Prior to 1997, only LAPD SWAT officers were authorized to carry .45 ACP caliber pistols, specifically the Model 1911A1 .45 ACP semiautomatic pistol.