How Did Gunman Go From Typical Suburban Life to Attack?

Investigators are trying Uncover the motive of who killed four Marines at two US military sites. Muhammad Youssef Abdulazeez seemingly had a typical suburban American upbringing. Officials said the man from Hixson Tennessee did not appear to have been on the radar of federal authorities before the bloodshed Thursday. Abdulazeez was killed by police. Federal authorities were looking into the possibility the rampage was an act of terrorism but said there was no evidence yet that anyone else was involved. Residents in the quiet neighborhood where Abdulazeez was believed to have lived in a two-story home said they didn't know him or his family well.
Abdulazeez got an engineering degree from the University of Tennessee at Chattanooga in 2012 and interned at the Tennessee Valley Authority, the federally owned utility that operates power plants and dams across the South.