New details on slain Texas gunman

Texas Governor Greg Abbott says the public needs to remain vigilant following this weekend's deadly shooting at an Austin bar. As long as this war is going on, we need to be safe against potential attacks.

The gunman, who police identified as Ndiaga Diagne, was wearing a hoodie that said "Property of Allah" when he opened fire at the Downtown bar Buford's, first with a pistol, and then an AR-style rifle. The guns were required legally, I believe, in 2017, out of San Antonio.

Police officers shot and killed the 53-year-old, who was a naturalized US citizen originally from Senegal. [GUNFIRE] Oh, my god!

Investigators later found an Iranian flag and pictures of Iranian leaders at his home. We want to make sure that we have our facts 100% correct, or at least we've tracked down every possible lead that we can. We owe that to the victims and their families.

Sources tell CBS News they believe the gunman acted alone, and are looking through his online history for more information. Come out and shoot dozens of people, that's an act of terrorism. I don't care what the motivation behind it is.

University of Texas student Nathan Comeaux left Buford's minutes before the shooting that injured some of his friends and killed others. If I had stopped to grab water, or if I'd had seen a friend on the way out of the bar, stayed for four or five more minutes, now I'm on the patio when he drives by in the car.

The University of Texas campus is less than two miles away, where there are increased patrols this week. Jason Allen, CBS News, Austin. CBS News Correspondent Camilo Montoya-Galvez joins us now from Austin. Camilo, CBS News obtained a new image of the shirt the suspected gunman was wearing. What does this tell you? CAMILO MONTOYA-GALVEZ: Good evening, Lindsey. The photo we obtained was taken right after the shooter was killed by local police officers here in Austin, Texas, after that deadly attack at the bar. We understand that the photo appears to show that the man-- who, as you underscored, was born in Senegal and came to the US in 2000-- had been wearing a shirt with the design of the Iranian flag. We also previously reported, Lindsey, that he was wearing a hoodie above that shirt that said "Property of Allah." And that is critically important, Lindsey, because the attack here in Austin occurred roughly a day, 24 hours, after American forces and Israeli military forces conducted those operations against Iran, killing that country's Supreme Leader. And of course, it looks like officials are trying to determine categorically whether this man was, at the very least, in part motivated by that attack to carry out that mass shooting. We also understand that this man acquired American citizenship back in 2013 after becoming a green card holder, or a permanent US resident, back in 2006 after marrying a US citizen. And that he had, at the very least, one arrest here in Texas dating back to 2022 after a car collision. And again, while officials, Lindsey, are probing that question of potential terrorism activity in this case, they still maintain that the motive is still not determined completely. And we know that two law enforcement sources told CBS News that investigators said the shooter had prior mental health episodes in Austin. But law enforcement said today that he wasn't immediately known to them. What have authorities told us about the victims? Well, Lindsey, the two victims of the attack so far have been identified by Austin Police Department officials as 19-year-old Ryder Harrington and 21-year-old Savita Shan. We understand that the two victims of that attack at the bar in Austin were college students, and the young age of the victims really does underscore the tragic nature of this deadly shooting, Lindsey. Our CBS News colleague and I were actually out that night celebrating, and we saw hundreds of people, most of them young, most of them college students, celebrating, dancing, having drinks with friends and other colleagues. And obviously, that night took a really tragic turn in only a matter of hours, Lindsey. OK. Camilo Montoya-Galvez, thank you.