Members of Germany's elite police unit, the Spezialeinsatzkommando, or SEK, demonstrate an abseil deployment from a helicopter during a media event on March 20, 2012 in Minden, Germany. The SEK is the special response team of Germany's state police force and typically deploys in high-risk situations, such as bank robberies, hostage takings and the arrest of armed and dangerous fugitives. (Photo by Thomas Starke/Getty Images)

An Occupy Wall Street protestor is arrested by the police during a march from Zuccotti Park to Union Square on March 24, 2012 in New York City. The Occupy Wall Street movement has seen a resurgence in recent weeks in part due to new protests over the killing of Florida teen Trayvon Martin. (Photo by Andrew Burton/Getty Images)

An injured fan is helped by a riot policeman during clashes between Red Star Belgrade and Partizan Belgrade fans in the stadium before the teams' Serbian Superliga soccer match in Belgrade, April 25, 2015. Serbian league leaders Partizan Belgrade held champions and bitter city foes Red Star to a 0-0 draw in a derby match marred by bad crowd trouble before kickoff on Saturday. The start was delayed for 45 minutes after home Red Star supporters pelted riot police with seats and flares, forcing officers to retreat from the north tier that houses the club's diehard fans. (Photo by Marko Djurica/Reuters)

Police officers detain a woman during an unsanctioned rally in the center of Moscow, Russia, Saturday, July 27, 2019. Russian police are wrestling with demonstrators and have arrested hundreds in central Moscow during a protest demanding that opposition candidates be allowed to run for the Moscow city council. (Photo by Pavel Golovkin/AP Photo)

Firefighters attempt to put out a fire at an abandoned building with the protection of St. Louis City Police in St. Louis, Missouri August 19, 2015. Police fatally shot a black man they say pointed a gun at them, drawing angry crowds and recalling the racial tensions sparked by the killing of an unarmed African-American teen in nearby Ferguson, Missouri, just over a year ago. (Photo by Lawrence Bryant/Reuters)

A 10 week old stuffed Tiger cub and a Tortoise are displayed in a cabinet at an “Endangered Species” exhibition at London Zoo on September 12, 2011 in London, England. The exhibition is organised by “Operation Charm”, a Metropolitan Police partnership aimed at tackling the illegal trade in endangered wildlife and runs for one month at London Zoo. Items include the tooth of a sperm whale, Ivory carvings, and a stuffed Tiger. (Photo by Dan Kitwood/Getty Images)

Lady officers of the Philippine National Police force show the taped muzzle of their guns at a police camp in Taguig City, south of Manila, Philippines, 22 December 2014. Law enforcement units all over the country held a ceremonial taping of firearms as a counter measure against cases of indiscriminate firing and illegal discharge of service weapons during the upcoming Christmas and New Year celebrations. (Photo by Francis R. Malasig/EPA)

Afghan police officers secure a transportation headquarters that was besieged for two days last weekend, on May 14, 2011 in Kandahar, Afghanistan. Taliban gunmen and suicide bombers unleashed a major assault May 7, 2011 on locations in Kandahar that included the governor's compound, the mayor's office, police stations, and an intelligence agency headquarters. (Photo by Majid Saeedi/Getty Images)