Ruby Corado, second from right, and Selena Cruz whip their hair around playfully while joking with Lazema Mills, left, and Giselle Gartzog, right, at Casa Ruby, a drop-in and service center for transgender people in Washington, D.C. Through the center, Corado helps people find housing, medical care and get food. Lexey Swall/GRAIN for NPR hide caption
A protester holds a stone as police use water cannons on crowds near the new headquarters of the European Central Bank in Frankfurt, Germany. Michael Probst/AP hide caption
In 2010, Omar Thornton killed eight colleagues in Manchester, Conn., before killing himself. Private employers used to create their own rules about guns on their property. But over the past five years, many states have adopted laws that allow employees to keep firearms in their vehicles at work. Douglas Healey/Getty Images hide caption
As the mayor of Cali, Colombia, epidemiologist Rodrigo Guerrero (left) meets with the police once a week to review murder statistics. Courtesy of Prensa Alcaldía de Calí hide caption
Involuntary commitment to a hospital for mental illness can be a lengthy and complex process. A California law makes mandatory outpatient treatment an option. iStockphoto hide caption
Lt. Gen. Mark Milley speaks to reporters April 2 regarding the second shooting in five years on the Fort Hood Army post in Texas. Drew Anthony Smith/Getty Images hide caption
Explosions during the filming of the PG-13 hit The Dark Knight in Chicago in 2007. Nam Y. Huh/AP hide caption
Gun violence has become increasingly common in PG-13 movies like The Avengers, released in 2012. Zade Rosenthal/AP hide caption
An ambulance makes its way through revelers in Cardiff city center in Wales in 2010. New measures in the city have reduced injuries caused by violence. Matt Cardy/Getty Images hide caption
Somali women and children wait to get medicine in July 2008, from a clinic run by Doctors Without Borders about 20 miles south of Mogadishu. AFP/AFP/Getty Images hide caption
A police officer guards Cambodia's famed temple of Angkor Wat. The powerful city-state collapsed in 1431 after suffering through two decades of droughts. Heng Sinith/AP hide caption
Members of the 18th Street gang announce a truce during a press conference at a prison in San Pedro Sula on May 28. Leonel Cruz/AFP/Getty Images hide caption