Passenger describes erratic experience with the Uber driver accused of killing 6 people at random

A passenger who rode with an Uber driver who allegedly killed six people in Kalamazoo, Michigan has spoken out about the driver's strange and erratic behavior.

Saturday afternoon, the day of the killings, Uber driver Jason Dalton picked up Matthew Mellen, who told The Washington Post that Dalton's driving was so reckless, he nearly jumped out of the car.

"He was like asking me, 'Don't you want to get to your friend's house?' " Mellen said Dalton asked as he refused to slow down or stop.

Mackenzie Waite, Mellen's fiance, said he told her that Dalton picked up a phone call during the ride, and that the driver started acting strangely afterward.

"He blew through a stop sign, sideswiped a car, starting driving in [and] out of the other lane of traffic," Waite told the Post. "My fiance was just pleading with him to stop."

Once he was out, Mellen called 911. He also sent a message to Uber. Waite said Uber did not immediately respond, and police didn't get back to him for a description of the driver or car until 6:30 p.m.

Another man who rode with Dalton that day even jokingly asked "you're not the shooter, are you," according to local TV station 24 Hours News 8.

The man, Derek, who did not consent to his full name being used, told the TV station he ordered the Uber after he heard there were shootings nearby.

He figured it was a safer bet than walking.

Once in the car, his father brought up the killing spree, which was when Derek asked if he was the shooter.

Derek said Dalton replied that he was not, adding that he was "just tired."

He provided the reporter with a receipt from the ride. It showed that he was in all likelihood Dalton's last passenger before he was arrested. The arrest happened 20 minutes after Derek and his father were dropped off at a local hotel.

"It's a little jarring," he said after seeing Dalton's mugshot the next day. "I don't think that it's really set in yet."

Another pair of late-night riders were supposed to be picked up by Dalton, only to cancel at the last minute.

Carmen Morren told the Post she was at a bar along with her boyfriend when she was set to be picked up by Dalton just before 11:15 p.m.

That was an hour after Dalton's final shooting

"I said, 'Hang on a second. Let me finish my drink,' " she said. "It was by the grace of God we canceled."

Dalton passed a background check with Uber, per a company spokesman. He had no prior criminal record, multiple outlets reported.

"We are horrified and heartbroken at the senseless violence in Kalamazoo, Michigan," Joe Sullivan, Uber's chief security officer, said in a statement. "We have reached out to the police to help with their investigation in any way that we can."

Dalton, a former insurance company employee, was arrested without incident in the parking lot of a downtown Kalamazoo bar about six hours after the rampage began, per The New York Times.

Police said there is no known motive for the killings.