Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Silhouetted against the warm sunset skyline and the illuminated Tokyo Tower, visitors are reflected on the glass walls of a rooftop observation deck Thursday, January 21, 2021, in Tokyo. (Photo by Kiichiro Sato/AP Photo)

Models display an Autumn-Winter 2021/2022 collection creation by Andres Sarda lingerie brand during a fashion parade on the opening day of 73th Mercedes-Benz Fashion Week Madrid, at IFEMA Convention and Exhibition Center, in Madrid, Spain, 08 April 2021. (Photo by Mariscal/EPA/EFE)

The males, of the Oriental Garden species, are battling over territory in Solapur in the Maharashtra state, India on May 20, 2022. Occasionally, the tussle can be brutal, ending in a fatality with one lizard biting another to encourage them to retreat. (Photo by Ratnakar Hiremath/Solent News)

Suzanna Shahbazian of Canada competes in the Individual Exercises Final during Pan American Gymnastics Championships Rio de Janeiro 2022 at Carioca Arena 1 on July 09, 2022 in Rio de Janeiro, Brazil. (Photo by Buda Mendes/Getty Images)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)

Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Handout photo dated March 20, 2015 issued by Chester Zoo of lemurs looking at the eclipse over Chester Zoo. (Photo by Steve Rawlins/PA Wire/Chester Zoo)