A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)

Ucil, a trained monkey, takes part in a street performance on June 1, 2011 in Jakarta, Indonesia. The street performances usually involve the monkeys wearing masks, such as dolls' heads or attire to mimic humans, with the monkeys trained to act out human activities such as shopping, riding bicycles or other simulations of human behaviour. Poverty drives the handlers to exploit the monkeys in the hope of earning small change, but the effect and cruelty to the monkeys is a cause that charities such as the Jakarta Animal Aid Network are increasingly taking up. (Photo by Ulet Ifansasti/Getty Images)

Fire fighters, emergency service vehicles and a helicopter in Moskovsky Prospekt at the entrance to Tekhnologichesky Institut station of the St Petersburg metro in the aftermath of an explosion which occurred in a train at 14:40 Moscow timeon April 3, 2017. (Photo by Peter Kovalev/TASS)

Miguel Toribio, 11, puts a pistol belonging to his father into his belt, before demonstrating newly learnt skills from military-style weapons training, to a Reuters journalist in Ayahualtempa, Mexico, February 3, 2020. (Photo by Alexandre Meneghini/Reuters)

School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)

Peter Weiss, director of the Space Department of COMEX, (c) tests a pressurized suit identical to those used in space expeditions in the lava tunnel of “Caverne Gendarme” on October 12, 2018 in Saint-Philippe, the French overseas island of Reunion. Reunion could become a training site for astronauts. (Photo by Richard Bouhet/AFP Photo)

A woman from a group called “Las Patronas” (The bosses), a charitable organization that feeds Central American immigrants who travel atop a freight train known as “La Bestia”, passes food and water to immigrants on their way to the border with the United States, at Amatlan de los Reyes, in Veracruz state, Mexico October 22, 2016. (Photo by Daniel Becerril/Reuters)