The man who killed five US troops in Tennessee was acting alone, the FBI said Wednesday, adding it is too early to tell if he was "radicalised" or motivated by mental illness. Four US marines and a sailor were killed after Mohammad Youssuf Abdulazeez, 24, opened fire on two military centers in Chattanooga before dying in a shootout with police Thursday.
Authorities have said they are treating the case - reminiscent of other shooting rampages at US military installations - as an "act of terrorism." "At this time we are treating him as a home-grown violent extremist," FBI special agent Ed Reinhold told reporters. "We believe he acted on his own on that day."
Nearly 1,000 FBI agents are pursuing hundreds of leads as they try to understand what motivated Abdulazeez, a naturalised US citizen who was born in Kuwait. His family has spoken of a history of mental illness and drug abuse and said they sent Abdulazeez to stay with family in Jordan in hopes of getting his life back on track. Investigators are examining his overseas travel and his online history to see if he came into contact with extremists who may have encouraged him to carry out the attack.
"At this point it's too early in the investigation to determine whether or not he had been radicalised," Reinhold said. "We are pursuing that as a possibly but it's too early to tell." Reinhold urged the media to be "responsible when talking about the case" and "not to jump to conclusions about what happened."