Sens. Edward Markey, D-Mass., left, and Richard Blumenthal, D-Ct., display a photo of a plastic gun Tuesday, as they call for President Trump to reverse an administration decision to allow a Texas company to make blueprints for a 3D-printed gun available online. Trump announced over Twitter that he is "looking into" the sale of 3D plastic guns to the public. Matthew Daly/AP hide caption
Officials at the U.S. Government Publishing Office, headquartered in Washington, D.C., showed a "high degree of disregard" for procedures in awarding the 2020 census contract to the bankrupt printing company Cenveo, the agency's Office of the Inspector General found. Samantha Clark/NPR hide caption
U.S. Immigration and Customs Enforcement Executive Associate Director of Enforcement And Removal Operations Matthew Albence, testifies as the Senate Judiciary Committee holds a hearing on the Trump administration's policies on immigration enforcement and family reunification efforts, on Capitol Hill on July 31, 2018. J. Scott Applewhite/AP hide caption
Traders work on the floor at the closing bell of the Dow Industrial Average at the New York Stock Exchange on July 26, 2018 in New York. Bryan R. Smith/AFP/Getty Images hide caption
Lauren Geoghegan cycling through Africa. Courtesy of Simply Cycling hide caption
The mother orca, known as J-35, pushes her dead calf to the surface last week off the coast of Victoria, British Columbia, Canada. The infant orca died shortly after its birth, but its mother has been observed carrying it with her in the days afterward. Michael Weiss/Center for Whale Research via AP hide caption
High-speed tracking dogs have been a game-changer in the fight against rhino poaching in South Africa. Their success depends on their ability to work as a team, which means they sleep and eat in the pack-sized enclosures shown above. David Fuchs hide caption
North Korean leader Kim Jong Un shakes hands with U.S. President Trump during their summit on June 12 in Singapore. Kevin Lim/The Straits Times/Getty Images hide caption
Actor Alan Alda, shown here in 2016, says he has been diagnosed with Parkinson's disease. Evan Agostini/Evan Agostini/Invision/AP hide caption
President Trump believes his emphasis on immigration is critical to rallying his voters this fall, and he may be right. They may care more about the promise of a wall than they have about his promise that Mexico would pay for it. Win McNamee/Getty Images hide caption
Afghan policemen stand guard outside the Imam Zaman Shiite mosque the day after a suicide attack during Friday evening prayers last October. WAKIL KOHSAR/AFP/Getty Images hide caption
Blood samples of people living with HIV in a laboratory at the AIDS Research Center in Abidjan, Ivory Coast. Sia Kambou/AFP/Getty Images hide caption
Two years after Uber paid $680 million to buy the self-driving truck startup Otto, the company is folding that effort. In this photo from 2016, an Otto engineer sits behind the steering wheel of a self-driving, big-rig truck during a demonstration in San Francisco. Tony Avelar/AP hide caption
Facebook says it is still in early stages of an investigation and is sharing information with U.S. law enforcement and Congress. Thibault Camus/AP hide caption
A man in Tehran looks at a newspaper with a picture of President Trump on the front page on Tuesday. Iran's currency traded at a fresh record-low of 119,000 to the dollar today, a loss of nearly two-thirds of its value since the start of the year as U.S. sanctions loom. Trump says he's willing to meet with Iranian leaders, but Iran doesn't seem eager to sit down. Atta Kenare/AFP/Getty Images hide caption