Shocking new details are emerging about 12 hours after the horrific mass shooting at a downtown Austin, Texas, bar early Sunday, with New York Post sources indicating that the deceased shooting suspect, Ndiaga Diagne, a U.S. citizen born in Senegal and living in Texas, allegedly carried out the attack that left three people dead and 14 injured including three in critical condition, with federal agents examining whether the attack was potentially motivated by US-Iran conflict.

Austin Police Chief Lisa Davis told reporters that officers arrived at Buford's bar, a popular beer garden on West Sixth Street in the downtown metro area.

The early investigation shows that Diagne circled the block around the bar several times in an SUV before the shooting, Davis said at a news conference.

Footage posted on X of the aftermath of the mass shooting is absolutely horrifying.

Alex Doran, a special agent with the San Antonio FBI field office, told reporters that the agency is working with local police on the investigation.

"There were indicators that on the subject and in his vehicle that indicate potential nexus to terrorism," Doran said. "Again, it's still too early to make a determination on that."

Diagne is a naturalized citizen from Senegal who has been in the U.S. for 15 years. Sources told NYPost that the shooter had a Quran in his vehicle and was dressed in clothing described as Islamic garb when he fired on the bar with a handgun, as well as a long rifle.

Sources told NYPost that investigators are examining whether the gunman may have been motivated by the U.S. strikes on Iran earlier in the day.

The shooting is likely to intensify scrutiny of U.S. border security and mass migration threats already in the Homeland, especially as former CIA targeting officer Sarah Adams has repeatedly warned about foreign-trained Islamists already on U.S. soil.

The question is whether this was an isolated incident (lone wolf) or an early signal of an emerging threat cycle, where the strike on Iran could accelerate copycat attacks and or activate terror cells.