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)

Cat lounges and makes itself at home at the new Cat Café by Purina ONE on Wednesday, April 23, 2014 in New York. (Photo by Amy Sussman/Invision for Purina ONE/AP Images)

“A Brazilian hotel was evacuated in the capital, Brasilia, on Monday after a man took hostage an employee who was held for hours before he was safely released to police. Firefighters and police cordoned off the area and about 300 guests and other employees left the hotel – some reportedly told to leave by the man who took the employee hostage”. – Associated Press. (Photo by Evaristo Sa/AFP Photo)

A priest comforts one of the relatives of the victims, before a mass in their memory, as Lebanon marks one-year anniversary of Beirut port explosion, at the port in Beirut, Lebanon on August 4, 2021. United in grief and anger, families of the victims and other Lebanese came out into the streets of Beirut on Wednesday to demand accountability as banks, businesses and government offices shuttered to mark one year since the horrific explosion. (Photo by Aziz Taher/Reuters)

A man invades the Red Carpet and is held by security at the “How To Train Your Dragon 2” Premiere at the 67th Annual Cannes Film Festival on May 16, 2014 in Cannes, France. The man stuck his head up America`s skirt before being dragged away by security. Pictured: Djimon Hounsou, Cate Blanchett, America Ferrera and Kit Harington. (Photo by Camilla Morandi/IPA)

A man protesting the Ferguson grand jury decision to not indict officer Darren Wilson in the Michael Brown case is arrested while marching through the streets on December 1, 2014 in New York City. Brown, an 18-year-old black man, was killed by Darren Wilson, a white Ferguson, MO police officer, on August 9. (Photo by Andrew Burton/Getty Images)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)