On Sunday, two gunmen shot a security guard protecting a building housing a cartoon convention seeking the best depiction of the Muslim prophet, Muhammad.
Elton Simpson is one, the identity of the other attacker is currently unknown. In 2010, Simpson was found guilty of making false statements to the FBI about going to Somalia. Extra ammunition was found in their car, but no bombs.
Eric Aasen, digital news editor at KERA, the NPR affiliate in Dallas, Texas, who is reporting on the shootings in Garland
David Schanzer, professor of Public Policy, Duke University's Sanford School of Public Policy, and director of the Triangle Center on Terrorism and Homeland Security.