In this image taken from video on Jan. 15, police officers Edward Sarama (from left) and Robert McGuire try to talk to officer Matt Dougherty, who is pretending to be mentally ill, during a training simulation at Montgomery County Emergency Service in Norristown, Pa. Michael Rubinkam/AP hide caption

itoggle caption Michael Rubinkam/AP

Classrooms across Gaza are crowded with as many as 50 or 60 students, principals say, as dozens of school buildings have been destroyed or damaged, or are still housing people who lost their homes. Emily Harris/NPR hide caption

itoggle caption Emily Harris/NPR

Scientists and engineers at the Indian Space Research Organization (ISRO) monitor the Mars Orbiter Mission (MOM) in Bangalore, India on Sept. 15. MOM is expected to enter into Mars orbit on Wednesday. Jagadeesh NV /Landov hide caption

itoggle caption Jagadeesh NV /Landov

President Obama signs H.J. Res 124, which includes appropriations to train and arm moderate Syrian rebels. For now, the effort will be paid for from an account meant to wind down the war in Afghanistan. Evan Vucci/AP hide caption

itoggle caption Evan Vucci/AP

A Ravens fan trades in her Ray Rice jersey Friday after he was cut from the team over allegations of domestic abuse. Patrick Semansky/AP hide caption

itoggle caption Patrick Semansky/AP

Low water levels, like at this reservoir near Gustine, Calif., bring birds and mosquitoes together and help transmit West Nile virus to humans. Rich Pedroncelli/AP hide caption

itoggle caption Rich Pedroncelli/AP

A plane flies over the Bardarbunga volcano as it spews lava and smoke in southeast Iceland on Sept. 14. The Bardarbunga volcano system has been rocked by hundreds of tremors a day since mid-August, prompting fears the volcano could explode. Bernard Meric/AFP/Getty Images hide caption

itoggle caption Bernard Meric/AFP/Getty Images

Syrian Kurds with their livestock wait behind a border fence near the southeastern town of Suruc in Sanliurfa province on Monday. Some 100,000 Kurds have fled from Syria into Turkey amid intense fighting between peshmerga forces and ISIS. Murad Sezer/Reuters/Landov hide caption

itoggle caption Murad Sezer/Reuters/Landov