Los Angeles District Attorney Jackie Lacey announced she has asked a judge to wipe out and seal cannabis-related convictions dating back to 1956. It's the culmination of a partnership with the nonprofit group Code for America which used computer-based algorithms to identify eligible cases. Marcio Jose Sanchez/AP hide caption
A flyer reminding customers about vaping-related deaths and illnesses, on display in a Seattle vape store. The Washington State Board of Health recently passed a four-month emergency ban on flavored vaping products. It applies to products that contain either THC or nicotine. Jovelle Tamayo/Bloomberg/Getty Images hide caption
Vaping illness is a growing concern, according to the Centers for Disease Control and Prevention. The agency's principal deputy director, Dr. Anne Schuchat, announced new numbers Thursday. Andrew Harnik/AP hide caption
Investigators have found that cannabis-containing vaping products are linked with many of the reported cases of vaping-related lung illness. Mike Wren/AP hide caption
Workers prune marijuana plants at a Clever Leaves greenhouse in Pesca, Colombia. The company employs over 450 people. Courtesy of Clever Leaves hide caption
U.S. health officials are again urging people to stop vaping until experts figure out why some are coming down with serious respiratory illnesses. Richard Vogel/AP hide caption
The New York State Department of Health said Thursday that it is looking at vitamin E acetate as a potential cause of severe pulmonary illness cases in the state that have been associated with vaping. Daniel Becerril/Reuters hide caption
Marijuana use is risky for teens and pregnant women and can be habit-forming, says the U.S. surgeon general. Jane Khomi/Getty Images hide caption
California says revenue from marijuana sales has risen — but analysts say the illegal market is still thriving. Here, an employee puts down an eighth of marijuana after letting a customer smell it at the Magnolia cannabis lounge in Oakland. Elijah Nouvelage/Reuters hide caption
A cannabis flower at Glass House Farms in Carpinteria, Calif., is almost ready for harvest. This farm uses greenhouses, allowing for five harvests a year. Claire Heddles/NPR hide caption
Scientists exhumed 10 wooden braziers from eight tombs at the ancient Jirzankal Cemetery in what is now western China. Many of the braziers held stones that were apparently heated and used to burn cannabis plants. Xinhua Wu/Science Advances hide caption
A bipartisan group of attorneys general is urging Congress to pass legislation that would make it easier for banks to handle money involved in the legal cannabis industry. Brennan Linsley/AP hide caption
Cannabis: The Illegalization of Weed in America, by Box Brown First Second hide caption
Research shows a link between marijuana use and psychosis. Kirill Vasikev/EyeEm/Getty Images hide caption