ODESSA, Tex. — Monette Rodriguez remembers the oil field truck-driver who lived at the Peppertree Place Apartments. He had the phrase “Oilfield Mafia” displayed on the back window of his blue Dodge Challenger. And he liked to party — neighbors complained that women made frequent visits at all hours of the night to his apartment.
The truck driver was Seth A. Ator, 36, the gunman who waged a mobile mass shooting that spread panic and bloodshed across the West Texas sister cities of Midland and Odessa on Saturday. Ms. Rodriguez, 41, a former Peppertree Place manager, said the gunman used to live in the complex several years ago. She said he was never disrespectful to her, but she recalled walking into his apartment after he had moved out and finding a large amount of pornographic material he had left behind.
“That, to me, was very disturbing,” Ms. Rodriguez said.
On Monday, the depth of the gunman’s erratic and nomadic life and behavior became clearer, as the authorities described how he was fired from his trucking job the morning of the shooting, called the F.B.I. tip line and was even on the phone with 911 dispatchers as he carried out the attack. He had been living a kind of drifter’s life in the West Texas oil fields, estranged from many relatives, grappling with the suicide of his older sister and ditching apartment life for a secluded shack-style building
where he shot his firearms outside late into the night.
“He was on a long spiral of going down,” said Christopher H. Combs, the special agent in charge of the F.B.I.’s San Antonio office.
One friend of the family said the gunman had a long history of mental problems, trouble with the law and making racist comments. “The man should have never had a gun near his hand ever,” said the friend, who declined to give his name because he did not want to jeopardize his relationship with the family.
But the suspect did have guns, including the military-style rifle he used on Saturday. He opened fire on state troopers who tried to pull him over for a simple traffic violation in Midland, sped down Interstate 20 shooting motorists and hijacked a postal van as he continued his spree in Odessa. The authorities said he killed seven people, including the female driver of the postal van, before officers ended the chase outside a movie theater in Odessa by shooting and killing him.
The chief of the Odessa Police Department, Michael Gerke, told reporters on Monday that the gunman went to work on Saturday morning at an oil field services company, was there for a short time and was fired by the company. Immediately afterward, both the gunman and representatives of the company called 911, each lodging complaints against the other.
A short time later, the gunman called the F.B.I. national tip line “but makes no threats of any type of violence,” Chief Gerke said.
Special Agent Combs said the gunman had previously called the agency’s national tip line multiple times, and described the call from the gunman on Saturday as “rambling statements about some of the atrocities that he felt he had gone through.”
The state troopers who sought to stop the gunman on Interstate 20 knew none of this information when they tried to pull him over at 3:13 p.m. for failing to signal a left turn, officials said. Later, during the attack, the gunman was on the phone with 911 and admitted that he was the assailant at one point, the authorities said.
“He said he was the guy doing it,” Special Agent Combs said.
Officials declined to comment on the nature of the employment dispute with the oil field services company, which they identified as Journey Oilfield Services, but they said his firing had not been established as the primary motive.
“When he showed up to work, he was already enraged,” Special Agent Combs said, adding that “it is not because he got fired.”
Special Agent Combs defended the F.B.I.’s handling of the gunman’s repeated past phone calls to the agency.
“I can tell you that thousands of people call law enforcement every day with crazy ramblings,” he said, adding, “That’s not the bar. The bar is when somebody makes threatening comments or when you see actions that are leading to illegal behavior. And that’s hard. That’s very hard because of the amount of calls that we get.”
It was unclear whether the gunman had legally bought the rifle, an AR-15-style weapon, and whether anything in his background, including his misdemeanor offenses and psychiatric history, had prevented him from buying the gun. The authorities said he had once applied to buy a gun but was denied, but they did not discuss the details of that transaction.
Gov. Greg Abbott wrote on Twitter that the gunman had previously failed a background check to buy a gun in Texas and had not gone through a background check for the weapon he used in the Odessa attack. “We must keep guns out of criminals’ hands,” Mr. Abbottosted on Monday.
Several of those injured were treated and released, but at least 10 remained hospitalized on Monday. The wounded included a state trooper, a Midland officer, an Odessa officer and a 17-month-old girl. The toddler, Anderson Davis, who had shrapnel in her chest as well as injuries to her teeth and mouth, was released from a Lubbock hospital on Sunday.
The youngest person to die was Leilah Hernandez, 15, a sophomore and basketball star at Odessa High School who was with her family at a car dealership when she was shot. Her older brother was planning to buy a truck. At a vigil on the campus of the University of Texas of the Permian Basin on Sunday evening, Leilah’s friends held signs reading #23, Leilah’s number.
“Just Friday we were talking, and she was telling me how proud she was of me,” said one of Leilah’s friends at the vigil, Sajeili Carrasco, 15. “And she was giving me words of advice because I wasn’t having too good of a morning. It was already time to go to class, so we said our I-love-yous and hugged, but I wish I would’ve held on longer.”
The gunman left a total of 32 victims — seven killed and 25 wounded. The authorities released their names on Monday. In addition to Leilah, the six others who were killed were identified as Edwin Peregrino, 25; Mary Granados, 29, the driver of the postal van; Kameron Karltess Brown, 30; Raul Garcia, 35; Joe Griffith, 40; and Rodolfo Julio Arco, 57.
The gunman was born a few hours north of Odessa in the Texas Panhandle, in Potter County, which includes Amarillo. But he largely grew up in Central Texas. He went to high school in Lorena, a small town near Waco, and attended McLennan Community College in Waco for one semester in fall 2000. It was not long until his problems with the police became more frequent, and tragedy struck his family.
He was arrested in August 2001 in McLennan County in the Waco area on misdemeanor charges of criminal trespass and evading arrest, according to state data. In 2014, he was arrested by the Odessa police for public intoxication. One year later, his older sister, Elissa Breanne Ator, a graduate of Texas A&M University, committed suicide. She was 34.
Two years after her death, in 2017, he again had a run-in with the law, receiving a misdemeanor traffic violation in Ector County, which includes Odessa. He fought the case in court, appealed the charge and had it dismissed one year later, according to court records.
His interactions with the police probably made it hard for him to get and maintain steady employment as a truck driver. In recent years, he seemed to have moved from job to job and from place to place. He had been living in the rural and remote building in recent months on the outskirts of Odessa. It was more a ramshackle warehouse than a residence, with metal walls and a patched-up wooden shed that sat on top as a makeshift upstairs room.
Special Agent Combs said the suspect’s residence was “very strange” and reflected his mental state. “Anyone who was there or drives by sees that is not the residence of somebody who is completely in control,” he said. “It’s a mess.”
A neighbor, Lourdes Tarango, 29, an Odessa middle school teacher who lives about a block away, said she would frequently hear gunshots coming from his property, usually after midnight. “We figured it was nothing since there is so many rattlesnakes here,” she said. “We figured maybe he was shooting at some animals.”