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)

A four-legged robot dog called SPOT patrols a park as it undergoes testing to be deployed as a safe distancing ambassador, following the coronavirus disease (COVID-19) outbreak, in Singapore on May 8, 2020. (Photo by Edgar Su/Reuters)

A woman walking with a dog battles through heavy rain and blustery conditions during the morning on Wimbledon Common in London on October 2, 2020 as storm Alex brings strong 70mph gale force winds to many parts of the UK. (Photo by Amer Ghazzal/Alamy Live News)

Aerial view of a clear and turbid landscape at the intersection of the Sanjiang Estuary during the flood season on July 4, 2023 in Nanning, Guangxi Zhuang Autonomous Region of China. (Photo by Chen Guanyan/China News Service/VCG via Getty Images)

Senior citizens sit outside US retailer Victoria’s Secret in Beijing, China, 08 April 2025. On 07 April, 2025, US President Donald Trump threatened China with an additional 50 percent tariff on goods imported into the US if it does not withdraw a 34 percent tariff it imposed on US imports into China. The 34 percent tariff China set was in response to Trump’s earlier 34 percent tariff on Chinese imports into the US. Trump gave China a deadline of 08 April to withdraw its tax, or it will face the 50 percent additional tax. (Photo by Jessica Lee/EPA/EFE)

A woman raises her fist during events to mark Juneteenth, which commemorates the end of slavery in Texas, two years after the 1863 Emancipation Proclamation freed slaves elsewhere in the United States, amid nationwide protests against racial inequality, in the Harlem neighbourhood of Manhattan, in New York City, New York, June 19, 2020. (Photo by Andrew Kelly/Reuters)

A French rock climber named Jean Michel Casanova scales the 172-meter-high steel derrick of the Bailong Elevator, also known as Bailong Sky Ladder, with his bare hands at the Wulingyuan Scenic Area on June 28, 2023 in Zhangjiajie, Hunan Province of China. (Photo by Deng Daoli/VCG via Getty Images)

A performer plays the violin as a passerby wears a mask in Times Square as Manhattan is shrouded in haze and smoke which drifted south from wildfires in Canada, in New York City, New York, U.S., June 7, 2023. (Photo by Maye-E Wong/Reuters)