Pittsburgh Police hats with checkered bands, which are dark navy blue and gold in color, popularly known as the "Sillitoe Tartan" and named after its originator, Percy J. Sillitoe, Chief Constable of Glasgow, Scotland, in the 1930s. While the checkered band is a common police symbol in the United Kingdom, Australia and some European countries, the Chicago Police Department, Cook County Sheriff's Police, the Allegheny County Sheriff's Office, and the Pittsburgh Bureau of Police are the only police forces in the United States that have adopted it as part of their uniforms. As recently as July 1930, police were required to wear
Police use of firearms in the United Kingdom was considerably tightened, many officers had their firearm authorisation revoked, and training for the remainder was greatly improved. As of 2005, around 7% of officers in London are trained in the use of firearms. Firearms are also only issued to an officer under strict guidelines. To allow armed officers to respond rapidly to an incident, most forces have patrolling Armed Response Vehicles (ARVs). ARVs were modelled on the Instant Response Cars introduced by the West Yorkshire Police in 1976, and were first introduced in London in 1991, with 132 armed deployments being made that year. Although largely attributable to a