ODESSA, Texas (CBSDFW.COM) – Federal agents are still looking into the history of the assault-style rifle used in a Labor Day weekend rampage in Odessa.

CBS 11 News reported Wednesday that the FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives connected the rifle used to a home in Lubbock.

Until about 9 p.m. Wednesday night, agents were seen in the normally quiet neighborhood.

Sources close to the investigation said the home is connected to a person suspected of building and selling the style rifle to the Odessa shooter, Seth Aaron Ator, 36.

CBS 11 News reached out to the homeowner but he didn’t return any messages.

Neighbors who know him said they were unaware of him making or selling firearms.

The Associated Press reported Thursday that investigators were looking more at the “transfer” of the weapon, from the home to the shooter.

Seven people were killed and around two dozen were injured in the shooting that spanned for more than an hour from Midland to Odessa, about 140 miles south of Lubbock.

Officers killed Ator on Saturday outside a busy Odessa movie theater after a spate of violence that spanned 10 miles. He fired indiscriminately from his car into passing vehicles and shopping plazas, and at one point hijacked a U.S. Postal Service mail truck, killing the driver.

Ator failed a federal firearms background check in 2014 due to a “mental health” issue.

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