Sgt. Victor Medina suffered brain damage in 2009 when a roadside bomb exploded in Iraq. Blake Gordon/Aurora Photos hide caption

itoggle caption Blake Gordon/Aurora Photos

Heirloom beets served at Bibiana Restaurant in downtown Washington, D.C. Joseph Silverman/The Washington Times /Landov hide caption

itoggle caption Joseph Silverman/The Washington Times /Landov

Dr. Alex Dromerick co-directs the Brain Research Center at the National Rehabilitation Hospital. Here he observes Stephen Jones, a policeman who was involved in a motorcycle accident. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR

The Mall of America in Bloomington, Minn., has implemented a security program aimed at aiding the government identify suspected terrorists. Jim Mone/AP hide caption

itoggle caption Jim Mone/AP

The Mall of America, one of the nation's largest shopping and entertainment venues, is also home to its own counterterrorism unit. Dawn Villela/AP hide caption

itoggle caption Dawn Villela/AP

Sgt. Nathan Scheller was twice denied for a Purple Heart, though roadside bomb explosions left him with lasting cognitive damage. Above, Scheller walks with his wife, Miriam, and his family. NPR/Frontline hide caption

itoggle caption NPR/Frontline