ODESSA, Texas • The gunman in a West Texas rampage that left seven dead obtained his AR-style rifle through a private sale, allowing him to evade a federal background check that previously blocked him from getting a gun, a law enforcement official said.

The official spoke to The Associated Press on Tuesday on condition of anonymity because the person was not authorized to discuss an ongoing investigation.

Officers killed 36-year-old Seth Aaron Ator on Saturday outside a busy Odessa movie theater after a spate of violence that spanned 10 miles, injuring around two dozen people in addition to the dead.

Authorities said Ator “was on a long spiral of going down” and had been fired from his oil services job the morning of the shooting, and that he called 911 both before and after the rampage began.

Ator had previously failed a federal background check for a firearm, said John Wester, an agent with the federal Bureau of Alcohol, Tobacco and Firearms.

Wester did not say when Ator failed the background check or why.

Online court records show Ator was arrested in 2001 for a misdemeanor offense that would not have prevented him from legally purchasing firearms in Texas.

Federal law defines nine categories that would legally prevent a person from owning a gun, which include being convicted of a felony, a misdemeanor domestic violence charge, being adjudicated as a “mental defect” or committed to a mental institution, the subject of a restraining order or having an active warrant. Authorities have said Ator had no active warrants at the time of the shooting.

FBI special agent Christopher Combs said Monday that Ator called the agency’s tip line as well as local police dispatch on Saturday after being fired from Journey Oilfield Services, making “rambling statements about some of the atrocities that he felt that he had gone through.”

“He was on a long spiral of going down,” Combs said.

“He didn’t wake up Saturday morning and walk into his company and then it happened. He went to that company in trouble.”

Celeste Lujan, left, and Yasmin Natera hold a sign in honor of Leilah Hernandez during a Sunday vigil for victims in Odessa, Texas.

the associated press