Deadly Austin shooting that killed 3 may be 'act of terrorism,' FBI says

The FBI said a shooting that left three people dead and 14 others wounded in a downtown Austin, Texas, rampage early Sunday was "potentially an act of terrorism."

The suspect, identified as Ndiaga Diagne, was a 53-year-old naturalized U.S. citizen who was born in Senegal and lived in Pflugerville, Texas, multiple federal law enforcement sources told Fox News.

According to those sources, the shooter was wearing a sweatshirt that said "Allah" and an undershirt featuring an Iranian flag. Fox News has obtained a photo of the alleged mass shooter, armed with a rifle and in a sweater that says "property of Allah." Multiple federal sources tell Fox News that the suspect was naturalized in 2013 during the Obama administration. 

White House press secretary Karoline Leavitt said that President Donald Trump has been briefed on the Austin shooting. 

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The gunfire erupted just before 2 a.m. outside Buford's Backyard Beer Garden on West Sixth Street, a packed entertainment district, after the suspect in a large SUV drove around the block several times before opening fire, police said.

"Obviously, it's still way too early in the process to determine an exact motivation, but there were indicators on the subject and in his vehicle that indicate potential nexus to terrorism," Alex Dorn, acting special agent in charge of the FBI's San Antonio Field Office, said at a Sunday press conference.

"Again, it's still too early to make a determination on that. That's why we are investigating it very closely with our partners with Austin police department," Dorn added.

Sources say at least one search warrant involving Federal Bureau of Investigation agents is currently being executed in Pflugerville.

Jason Pack, a retired FBI supervisory special agent with more than two decades of service, said investigators believe Diagne may have acted alone rather than as part of a coordinated group, adding that mental illness is also being examined.

"My sourcing suggests he was not part of an organized cell," he said. "This looks like a lone actor who may have been inspired rather than directed."

The search warrant will likely cover Diagne's digital footprint, including his devices, social media accounts and communications, Pack added. 

"That is where investigators will look for a radicalization pathway or any contact with extremist networks," he said. "Associates, family, neighbors, and coworkers will be interviewed to build a behavioral baseline and identify any missed warning signs. ATF will trace the pistol and rifle to establish how and when he acquired them."

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When pressed by a reporter on whether the case involved domestic or international terrorism, Dorn said the Joint Terrorism Task Force is engaged.

"We're just at this point prepared to say that it was potentially an act of terrorism," he added.

Asked about the shooting, Republican Sen. John Cornyn of Texas on Sunday said in a Fox News Digital interview, "What it does emphasize to me is the importance of vetting people before they come across the border."

"Part of the problem is that the Biden administration, for four years, had open border policies and let who knows what into the country," Cornyn charged. "This isn't about people continuing to come into the country, because we know President Trump has secured the border. This is about what happens with people already here."

Police Chief Lisa Davis said the gunman "put his flashers on, rolled down his window and began using a pistol shooting out of his car windows, striking patrons of the bar that were on the patio and that were in front of the Bar."

The suspect then drove westbound on Sixth Street to Wood Street, parked, exited the vehicle with a rifle and continued shooting at pedestrians, Davis said.

"He never entered the bar," she added.

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Officers staged nearby for weekend crowds responded within about "55-56 seconds," Davis said. Police shot and killed the suspect at an intersection.

The shooting comes amid ongoing safety concerns along Austin's Sixth Street entertainment strip, which has seen multiple violent incidents in recent years as police and business owners work to improve crowd-control measures, according to local KVUE.

"There is chaos in front of that bar every weekend, OK? This is not a new thing," Hugo Mendez, owner of Blindside Tattoos and Blindside Lounge, told the outlet. "It's not necessarily Sixth Street. It's certain bars… that don't carry the standard."

Authorities have set up a Victim Services Unit hotline for families seeking information.