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)

Women walk on a sidewalk in northern Tehran, Iran, Thursday, January 9, 2020. (Photo by Vahid Salemi/AP Photo)

A traffic police officer directs vehicles at a street junction during sunset in Pyongyang, North Korea, Thursday, August 25, 2016. (Photo by Dita Alangkara/AP Photo)

Ivanka Trump poses with Kristina Hilko, Lauren Shovlin, and Anna Nesbitt, members of the Girls of Steel Robotics initiative, at the Astrobotic Technology facility in Pittsburgh, Pennsylvania on August 14, 2018. (Photo by Jason Cohn/Reuters)

The Mausoleum of the Giants, an immersive solo show of monumental sculptures by the artist Phlegm, is installed at Taylor’s Eye Witness Works in Sheffield, England on March 14, 2019. (Photo by Danny Lawson/PA Wire Press Association)

A woman in custume attends the 2021 New York Comic Con, at the Jacob Javits Convention Center in Manhattan in New York City, New York, U.S., October 7, 2021. (Photo by Brendan McDermid/Reuters)

Mary Earps of England makes a save during an England Training Session at St George's Park on April 02, 2024 in Burton upon Trent, England. (Photo by Naomi Baker/The FA via Getty Images)

Festival goers in Finsbury Park ahead of the Wireless Festival at Finsbury Park in London, United Kingdom on Friday, July 8, 2022. (Photo by James Manning/PA Wire Press Association)