Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

Two pins featuring former North Korean leader Kim Il Sung wearing different facial expressions are displayed in a glass case of Thomas Hui at his apartment in Hong Kong, China April 11, 2016. Collector Thomas Hui, 37, a former bank employee in Hong Kong, who is fascinated by North Korean pins and badges, has gathered over 100 featuring former leaders Kim Il Sung and Kim Jong Il, and has been buying and trading these Communist accessories since 2008. (Photo by Bobby Yip/Reuters)

This stirring collection of photos which offer a glimpse behind the scenes of army life have all been selected as winners in an annual competition. The remarkable pictures in the Army Photographic Competition show Britain's soldiers at work and play. They have been taken by amateur and professional soldier cameramen and include images from operations in Afghanistan, air shows and sporting events. The winners were announced at a ceremony held at the Army Headquarters in Andover in Hampshire. (Photo by Jamie Peters/MoD/Geoff Robinson Photography/REX Features)

A mascot of the Philippine National Police (PNP), named after their Chief Director General Ronald Dela Rosa, marches with members of the K9 units and the Special Action Force before the mass blessing for rescue dogs during the celebration of the feast day of St. Francis of Assisi, patron Saint of Animals, at the St. John Paul II parish church in Eastwood, Quezon city, metro Manila, Philippines October 2, 2016. (Photo by Romeo Ranoco/Reuters)

A resident gestures about the loss of his home following an overnight fire at the Addition Hills area in suburban Mandaluyong city east Manila, Philippines, Monday, November 14, 2016. Fire officials say the overnight fire destroyed hundreds of homes, rendered more than 5,000 people homeless and resulted in the death of two residents. (Photo by Bullit Marquez/AP Photo)

Students from Cambridge University in England make their way home along Trinity Lane after celebrating the end of the academic year at a May Ball in Trinity College on June 18, 2019. (Photo by Joe Giddens/PA Images via Getty Images)

Natalie Portman and Tessa Thompson speak at the Marvel Studios Panel during 2019 Comic-Con International at San Diego Convention Center on July 20, 2019 in San Diego, California. (Photo by Kevin Winter/Getty Images)

Hindu women worship the Sun god in the polluted waters of the river Yamuna during the Hindu religious festival of Chatth Puja in New Delhi, India, November 3, 2019. (Photo by Adnan Abidi/Reuters)