The FBI is doing a forensic examination on Mohammad Youssef Abdulazeez's cell phone, computer and trips to Jordan to determine if he was involved with ISIS, said Michael McCaul, Chairman of the House Committee on Homeland Security.
The republican congressman from Texas appeared on ABC's This Week on Sunday to talk about ISIS and it's threat to America.
McCaul didn't say whether his office believes right now if Abdulazeez was directly involved or influenced by ISIS, but he did talk about what kind of threats ISIS is to America today.
"We have the threat over the Internet," he said. "Which is a new threat that's out there. A new generation of terrorists."
To attack Americans, ISIS members from Syria "activate people in the United States," he said, targeting military installations and police officers.
Homeland security has discovered 60 cases in the last year of locating ISIS followers in America.
But McCaul said this is the kind of case they were most worried about the one that slips through the cracks.
"What keeps us up at night are the ones we don't know about," he said. "And I'm afraid this case falls into that category."
One of the biggest problems in keeping tabs on ISIS doings is the shear volume of activity. There are over 200,000 ISIS tweets per day Homeland Security has to keep track of, McCaul said.
"The chatter is so loud and the volume is so high, that it's a problem that's hard to stop," he said.
McCaul pointed out that Homeland Security thwarted a potential attack during the Fourth of July, and said he thinks the fight needs to go overseas. He wants to find the people who are sending these tweets.
He reiterated Homeland Security will be looking hard at this case.
"If it can happen in Chattanooga," he said. "It can happen anywhere, anytime, anyplace."
Read more about the attacks on Chattanooga military facilities