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)

Supporters of Pakistan Tehreek-e-Insaf (PTI) party of Prime Minister Imran Khan shout slogans outside the Parliament House building in Islamabad on April 3, 2022. Pakistan will go to the polls to elect a new government within three months after Prime Minister Imran Khan foiled an attempt to boot him from office April 3 by getting the president to dissolve the national assembly. (Photo by Aamir Qureshi/AFP Photo)

A supporter of Brazil's former President Luiz Inacio Lula da Silva, who is running for office again, flashes the letter L for “Lula” during a campaign rally with him in the Complexo do Alemao favela in Rio de Janeiro, Brazil, Wednesday, October 12, 2022. The presidential run-off election is set for Oct. 30. (Photo by Silvia Izquierdo/AP Photo)

Indian army training cadets perform “Kalaripayattu”, an ancient martial art from Kerala, during a combined display ahead of their graduation ceremony, at the Officers Training Academy (OTA), in Chennai, India on September 8, 2023. A combined display of training proficiency was organized at the OTA as a prelude to a passing-out parade of cadets. The combined display marks the culmination of the adventure training and showcases the skills and expertise of armed forces display teams. (Photo by Idrees Mohammed/EPA/EFE)

A Belarusian law enforcement officer approaches women, who react while sitting on the pavement during a rally of opposition supporters following the presidential election in Minsk, Belarus on August 10, 2020. Belarusian police clashed with protesters on Monday after the opposition accused President Alexander Lukashenko of rigging his re-election victory amid a chorus of criticism from Western leaders. (Photo by Vasily Fedosenko/Reuters)

Police officers in action during the eviction of the “Liebig 34” squat, at Friedrichshain district in Berlin, Germany, 09 October 2020. A local court ruled in favor of the eviction of the self-declared “anarcha-queer feminist” house project at Liebig street 34 in June 2020. The house project is considered a stronghold of the left-wing scene in the German capital. (Photo by Filip Singer/EPA/EFE)

Police officers detain a Navalny supporter during a protest in St. Petersburg, Russia, Tuesday, February 2, 2021. A Moscow court has ordered Russian opposition leader Alexei Navalny to prison for more than 2 1/2 years on charges that he violated the terms of his probation while he was recuperating in Germany from nerve-agent poisoning. Navalny, who is the most prominent critic of President Vladimir Putin, had earlier denounced the proceedings as a vain attempt by the Kremlin to scare millions of Russians into submission. (Photo by Dmitri Lovetsky/AP Photo)

A United Launch Alliance Delta IV heavy rocket carrying classified spy satellite cargo for the U.S. National Reconnaissance Office lifts off from Space Launch Complex 37B at the Cape Canaveral Space Force Station, Tuesday, April 9, 2024, in Cape Canaveral, Fla. This is the final flight of a Delta IV heavy rocket. (Photo by John Raoux/AP Photo)