Texas mass shooter Seth Ator made a pair of “rambling” phone calls to local cops and the FBI shortly before his rampage that left seven people dead — but gave no indication of the bloodshed he was about to unleash, authorities said Monday.

When Ator, 36, showed up for work Saturday as a trucker at Journey Oil Field Services, he was told that he’d been canned, officials confirmed in a press briefing.

“Right after that firing, he called 911 … and so did his employer,” said Odessa Police Chief Michael Gerke. “Basically they were complaining on each other.”

Ator, who made no threats in the call, split before cops arrived, then placed another call to the FBI’s national tip line.

“It was frankly rambling statements about some of the atrocities that he felt he had gone through,” said Bureau Special Agent in Charge Christopher Combs. “He did not make a threat during that phone call.”

But just 15 minutes after that second call, state troopers tried to pull over Ator for a minor traffic infraction, setting off a brutal chain of events.

Ator raised his AR-style rifle and wounded one of the troopers, then peeled off toward Odessa, indiscriminately firing at motorists and pedestrians along his path of destruction.

In Odessa, he shot dead and carjacked a USPS mail carrier, continuing his tear in her van until he was forced to a stop in the parking lot of a movie theater and shot dead by cops.

Despite the new information, authorities stressed that the investigation was ongoing and stopped short of saying they’d identified Ator’s motive.

“He was on a long spiral of going down,” said Combs, not elaborating on Ator’s descent. “He didn’t wake up Saturday morning and walk into his company and then it happened.

“He went into that company in trouble.”