A fellow officer comes to the aid of injured patrolman C.V. Satt, who was pelted with rocks and beer bottles during a clash between police and relief demonstrators in Denver September 23, 1935. (Photo by Henry G. Eisenhand/AP Photo)

Two revelers dressed as toy soldiers gesture toward a police officer in a patrol car during the traditional carnival parade in Wuerzburg, Germany, 15 February 2015. Under the motto “Carnival Parade is cool” about 160 groups with over 3,000 members took part in one of the biggest carnival parades in southern Germany. (Photo by Daniel Karmann/EPA)

Members of the Bavarian police and the Bundeswehr, the German armed forces, guard a vehicle checkpoint as they demonstrate a dynamic operation as part of the GETEX anti-terror exercises during a media event on March 9, 2017 in Murnau, Germany. (Photo by Philipp Guelland/Getty Images)

A woman on a bicycle rides past the remains of an Audi sedan set afire by an arsonist recently in Zehlendorf district in a street where two more cars were torched on August 23, 2011 in Berlin, Germany. Police have so far made no arrests in a series of arson attacks that have destroyed at least 70 cars within the last week and show no signs of abating. In recent years several hundred cars have been torched annually and police suspect left-wing radicals. The recent series of attacks, averaging about 10 a day, has been particularly severe. (Photo by Sean Gallup/Getty Images)

Riot police walk past burning garbage containers during heavy clashes with demonstrators during a 24-hour strike on March 29, 2012 in Barcelona, Spain. Spanish workers staged a general strike to protest the government's latest labour reforms, which are designed to help Spain lower its deficit within EU limits. (Photo by David Ramos/Getty Images)

Russian Police detain opposition supporters during a “March of Millions” protest rally against Vladimir Putin's return in Moscow, Russia on May 6, 2012. Over 650 people were arrested including opposition leaders. (Photo by Dmitry Schedrin, Rustem Adagamov, Andrey Stenin)

Rescuers carry an injured passenger on stretcher at Soshigaya Okura Station after stabbing on a commuter train, in Tokyo Friday night, August 6, 2021. A man with a knife attacked 10 passengers on a commuter train in Tokyo on Friday and was arrested by police after fleeing, fire department officials and news reports said. (Photo by Kyodo News via AP Photo)

In this Monday, July 24, 2017 photo, a police officer walks in front of a mural during a protest demanding an end to the current pension fund system, in Santiago, Chile. Protesters say the government pension system robs retirees of fair pension payments, and are demanding a new social security system with higher payments. (Photo by Esteban Felix/AP Photo)