An unknown number of guns are being built with the mechanisms, causing problems for the police and ATF officials. Photo: An ATF agent holds a generic unfinished receiver, back, and one that has been manufactured, front, at an ATF field office in Washington, on May 06, 2014. The ATF is trying to crack down on the trade in the makeshift guns by targeting shops and individuals who offer to turn the unfinished receivers into functional pieces for firearms. (Photo by Bill O'Leary/The Washington Post)

The Spirit of Ecstasy, also called “Emily”, “Silver Lady” or “Flying Lady,” was designed by English sculptor Charles Robinson Sykes and carries with her a story about a secret passion between John Walter Edward Douglas-Scott-Montagu (second Lord Montagu of Beaulieu after 1905, a pioneer of the automobile movement, and editor of The Car Illustrated magazine) and his love and the model for the emblem, his secretary Eleanor Velasco Thornton. Photo: Worker Ronald Little displays a finished “Spirit of Ecstasy”. (Photo by Stefan Wermuth/Reuters)

A cosplayer uses moving stairs during the first public day of the world's largest computer games fair Gamescom in Cologne, Germany August 23, 2017. (Photo by Wolfgang Rattay/Reuters)

Iraqis run for cover as they flee Mosul's Al-Tayaran neighbourhood on February 28, 2017, during an offensive by Iraqi forces to retake the area from Islamic State (IS) group fighters. Hundreds of civilians fled through the desert to escape fighting and privation in Mosul, joining thousands of others who left their homes as conditions worsen in the city's west. (Photo by Ahmad Al-Rubaye/AFP Photo)

Afghan paraglider Leeda Ozori, 21, walks after practicing in Kabul, Afghanistan September 14, 2015. She is one of a group of young Afghans taking to the skies of a capital where military helicopters and surveillance balloons are a far more familiar sight. Women in Afghanistan's conservative Muslim society are increasingly entering areas such as education, sports and the workplace, but most still wear the head-to-toe garment, the burqa. (Photo by Mohammad Ismail/Reuters)

Fog covers the African Renaissance Monument in Dakar, Senegal on February 17, 2021. (Photo by Zohra Bensemra/Reuters)

Israeli soldiers of the Search and Rescue brigade take part in a training session in Ben Shemen forest, near the city of Modi'in May 23, 2016. (Photo by Amir Cohen/Reuters)

Selfie picture shows Swiss pioneer Bertrand Piccard during the last leg of the round the world trip with Solar Impulse 2 over the Arab peninsula July 25, 2016. (Photo by Jean Revillard/Bertrand Piccard/Reuters/SI2)