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)

Convention goers dressed as bright colored Wookiees, a fictional species from the US epic space opera franchise Star Wars, prepare for a group photo outside the Comic Con 2016 in San Diego, California, USA, 22 July 2016. The San Diego Comic Con 2016 runs from 21 until 24 July. (Photo by David Maung/EPA)

Musician “Girli” poses for a portrait during London Fashion Week in London, Britain February 21, 2017. (Photo by Neil Hall/Reuters)

These are the stunning pictures of the night sky brilliantly capturing the lights and colors of the Milky Way glistening over desert landscapes. Taken in various locations across Australia and the United States from the Grand Canyon to the Coral Sea, the pictures perfectly show the bright lights of the starry skies. Here: Bisit Badlands, New Mexico. (Photo by Wayne Pinkston/Caters News)

Lizzy Cundy attends the UK premiere of The Eagle held at The Empire Leicester Square on March 9, 2011 in London, England.

A woman in costume checks her phone at the Star Wars Celebration convention in Anaheim, California, April 16, 2015. The Star Wars Celebration runs through April 19 at the Anaheim Convention Center. (Photo by David McNew/Reuters)

A Palestinian man reacts after his house was flooded by rain water in Khan Younis in the southern Gaza Strip, November 9, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

Jeff and Kelly Lyons clear the first obstacle while competing in the North American Wife Carrying Championship at Sunday River ski resort in Newry, Maine October 11, 2014. (Photo by Brian Snyder/Reuters)