The 36-year-old man who killed seven people during a shooting spree in West Texas over the weekend was a “violent, aggressive person” who liked targeting animals before he set his sights on the public, a neighbor said.

Rocio Gutierrez, who lived next to gunman Seth Ator in Odessa, told The Associated Press this week that Ator often would fire at animals, mostly rabbits, at all hours of the night.

"We were afraid of him because you could tell what kind of person he was just by looking at him," Gutierrez said. "He was not nice, he was not friendly, he was not polite."

This undated photo shows Seth Aaron Ator. The gunman in a West Texas rampage "was on a long spiral of going down" and had been fired from his oil services job the morning he killed seven people, calling 911 both before and after the shooting began, authorities said. (AP/City of Odessa/FBI)

TEXAS SHOOTING VICTIMS INCLUDE DAD GUNNED DOWN IN FRONT OF HIS WIFE, KIDS

Police officers killed Ator on Saturday outside a busy Odessa movie theater after a spate of violence that spanned 10 miles. His rampage also injured around two dozen people.

It was not his first run-in with the law.

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

BEFORE MASS SHOOTING, ATOR WAS 'ON A LONG SPIRAL DOWN', INVESTIGATOR SAYS

Police said the arrest took place in the county where Waco is located, hundreds of miles east of Odessa. Online court records showed he was charged then with misdemeanor criminal trespassing and evading arrest. He entered guilty pleas in a deferred prosecution agreement wherein the charge was waived after he served 24 months of probation, according to records.

Federal law, The Associated Press reported, defined nine categories that legally would prevent a person from owning a gun. The categories included being convicted of a felony, a misdemeanor domestic violence charge, being adjudicated as a "mental defect" or being committed to a mental institution, being the subject of a restraining order or having an active warrant. Investigators have said Ator had no active warrants at the time of the shooting.

An error occurred while retrieving the Tweet. It might have been deleted.

CLICK HERE TO GET THE FOX NEWS APP

Gov. Greg Abbott tweeted Monday that Ator didn't go through a background check for the weapon he used in Odessa. He did not elaborate, and a spokesman referred questions to the Texas Department of Public Safety, which didn't immediately respond to a request for comment.

Odessa officials on Monday released the names of those killed, who were between 15 and 57 years old. Among the dead were Edwin Peregrino, 25, who ran out of his parents' home to see what the commotion was; mail carrier Mary Granados, 29, murdered in her U.S. Postal Service truck; and 15-year-old high school student Leilah Hernandez, who had been walking out of an auto dealership.

The Associated Press contributed to this report.