U.S. officials identified the guman that unleashed a barrage of fire at a recruiting center and another U.S. military site a few miles apart in Chattanooga, Tennesee, Thursday, at Kuwait-born Muhammad Youssef Abdulazeezi.
The 24-year-old is a naturalized U.S. citizen who is believed to have acted alone in the attacks.
Abdulazeezi graduated from the University of Tennessee at Chattanooga in 2012 with a bacholor's degree in electrical engineering and was a student intern a few years ago at the Tennessee Valley Authority, the federally owned utility that operates power plants and dams across the South.
A U.S. official said there was no indication Abdulazeez was on the radar of federal law enforcement before the shootings. Federal authorities said they were investigating the possibility it was an act of terrorism, but have no evidence yet that anyone but a lone gunman was involved.