The Texas madman who went on a mobile shooting spree had been fired from his job just hours before his rampage — and had previously failed a background check, according to new reports.

Seth Ator, 36, had been axed from his trucking job a few hours before he killed seven and injured 22 in a spree in Odessa that started with a routine traffic stop on Saturday, authorities told the New York Times.

Odessa Police Chief Michael Gerke did not mention the firing at a press briefing Sunday, instead insisting there were “no definitive answers as to motive or reasons at this point.”

Ator used an “AR-type weapon” in his attack, and police say they are still investigating how he got it — especially in light of a revelation by state Rep. Tom Craddick, who said Ator had previously failed a background check, according to the Midland Reporter-Telegram.

No details were given as to what caused him to fail.

Ator first opened fire at state troopers who pulled him over in his gold Toyota pickup truck for a minor signaling infraction along a stretch of I-20 near Midland, Texas, on Saturday.

He then peeled off, firing indiscriminately out of the truck as he floored it toward Odessa, authorities said.

Along the way, he killed a Postal Service worker and hijacked her mail truck, continuing the spree, officials said.

He made his last stand in the parking lot of an Odessa movie theater, where he was killed in a shootout with cops.