Hours before the Tennessee shooting that killed five U.S. servicemen, the suspected gunman texted a close friend a link to an Islamic verse that included the line: ¡°Whosoever shows enmity to a friend of Mine, then I have declared war against him.¡±

The gunman¡¯s family said in a statement late on Saturday he had suffered from depression, and that they had experienced shock and horror over the violence.

The suspect¡¯s friend said he thought nothing of the text message at the time, but now wonders if it was a clue to Thursday¡¯s rampage in Chattanooga, which has re-ignited concerns about the radicalization of young Muslim men.