An 18-year-old gunman entered Robb Elementary School in Uvalde, Texas, on Tuesday with what law enforcement described publicly as a "long rifle" before killing at least 19 students and two adults.
As the investigation into the shooter’s motive continued Wednesday morning, officials said they are also working with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to learn more about the firearm and how it was obtained.
"He was in possession of a long rifle," Texas Department of Public Safety Lt. Chris Olivarez confirmed on "America’s Newsroom" Wednesday morning. "We are working with ATF to try to determine exactly the type of rifle, the capacity, when it was purchased, how it was purchased and how he was able to obtain this rifle."
Olivarez said the gunman, earlier identified as Salvador Ramos, had no criminal history or gang affiliations that would have raised any red flags when purchasing the firearm.
In an ATF briefing given to Texas state Sen. John Whitmire and shared with Fox News, the agency said the suspect "legally purchased two AR platform rifles at a local federal firearms licensee on two separate dates: May 17, 2022, and May 20, 2022."
One rifle was left in the shooter’s truck that crashed near the school, according to the briefing. The other rifle, identified as a Daniel Defense rifle, was found inside the school with the gunman.
The briefing also said that the suspect purchased 375 rounds of 5.56 ammunition.
A backpack with several magazines full of ammunition was dropped by the suspect near the entrance of the school, the agency said. What appeared to be seven 30-round magazines were also found inside the school. The agency said it was unclear whether they were expended as the scene is still being processed.
Fox News’ Bill Melugin contributed to this report.