The suspected gunman in Saturday’s mass shooting in Texas had been fired that morning, and called police and the FBI before his attack, US media report.
Odessa Police Chief Michael Gerke reportedly said both the shooter and his company rang 911 after he was fired but he left before police arrived.
FBI agent Christopher Combs described his phone statements as “rambling”.
“This did not happen because he was fired,” said Mr Combs. “He showed up to work enraged.”
Seven people were killed and at least 22 injured in the attack, which came four weeks after another gunman killed 22 people in the Texas city of El Paso.
Authorities have named the suspected attacker as 36-year-old Seth Aaron Ator. Chief Gerke said he had worked at Journey Oilfield Services.
There is as yet not thought to be any link to domestic or international terrorism.
Police pulled over the gunman’s vehicle shortly after 15:00 local time (20:00 GMT) between the cities of Midland and Odessa after the car did not indicate a left turn.
The shooter then fired at the officers before driving towards Odessa. He shot at random, targeting motorists and passers-by, before officers killed him outside a cinema.
At least 22 people were wounded, including 17-month-old girl Anderson Davis. A family friend told Buzzfeed News the child “has a hole in her bottom lip, a hole in her tongue, and her top and bottom teeth were knocked out”.
Greg Abbott, the Republican governor of Texas, tweeted that the suspect “had previously failed a gun purchase background check” in the state.
“We must keep guns out of criminals’ hands,” he wrote.
Non-profit research group Gun Violence Archive says nearly 10,000 people have died in US mass shootings this year.