Members of the FBI Evidence Response Team investigate the crime scene outside of the Curtis Culwell Center after a shooting occurred the day before, on May 04, 2015 in Garland, Texas.

ISIS claimed responsibility Tuesday for the attack at a Texas event featuring caricatures of the Prophet Muhammad — but did not provide evidence to support its claim.

Charlie Winter, an NBC News counter-terrorism consultant, confirmed that ISIS said in an official radio broadcast Tuesday that two of its "soldiers" had carried out the attack in Garland, Texas.