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)

Britain's Prime Minister Boris Johnson gestures during a visit to Darnford Farm in Banchory near Aberdeen in Scotland on September 6, 2019. Prime Minister Boris Johnson heads to Scotland on Friday in campaign mode despite failing to call an early election after MPs this week thwarted his hardline Brexit strategy. (Photo by Andrew Milligan/Pool via AFP Photo)

Nihon University professor and head of Nihon University Animal Medical Center Kazuya Edamura, 49, points to cat photos on a computer screen, which are used to train the AI of “CatsMe!”, an AI-driven smartphone application jointly developed by tech startup Carelogy and researchers at Nihon University that purports to tell when a cat is feeling pain, as he gives a lecture to students on diagnosing pain in cats, at the medical center in Fujisawa, south of Tokyo, Japan on June 11, 2024. (Photo by Issei Kato/Reuters)

Firefighters use a rope to rescue a group of people stranded in a flooded street on July 12, 2018 in Chengdu, Sichuan Province of China. A strong storm has hit many parts of southwest China's Sichuan Province since Monday, causing landslides and floods in the region. (Photo by Wang Hongqiang/Chengdu Economic Daily/VCG)

A group of children run into a fountain on the South Bank on August 1, 2011 in London, England. Temperatures in the capital reached around 27 degress today and are expected to hit 30 degrees by Wednesday. (Photo by Dan Kitwood/Getty Images)

A Belarussian tourist crosses the river as he takes part in “Search and rescue operations – 2016”, a three-day competition, near the village of Priselki, Belarus, November 25, 2016. Photo taken November 25, 2016. (Photo by Vasily Fedosenko/Reuters)

Drag Race UK alumni, Cheddar Gorgeous in the window of a Primark store in Manchester to celebrate the opening of the Photo by Fujifilm x Primark concession in Manchester on Wednesday, November 1, 2023. Fans are invited to visit the instore concession on the first floor in Primark on Market Street where Cheddar Gorgeous will be in a garment made up of over 1,000 Fujifilm INSTAX prints and designed by local fashion creator and artist, Mariusz Malon. (Photo by James Speakman/PA Wire)

Visitors look at an artwork “Hierarchy of Prosperity” created by Indonesian artist Eko Nugroho during the VIP preview of the art fair “Art Basel” in Hong Kong, Tuesday, March 22, 2016. A set of gold-plated metal cubes, tapestries embroidered by unknown North Korean artisans and bales of cardboard waste are among the highlights of the Art Basel Hong Kong fair opening this week. (Photo by Kin Cheung/AP Photo)