An Uber driver who shot and killed six people on Saturday night in Kalamazoo, Michigan, was picking up and dropping off passengers between his attacks, local news reports. The perpetrator, identified as Jason B. Dalton, killed six and injured two at three locations across southwest Michigan between the hours of 6 PM and 10:30 PM on Saturday. He was arrested a few hours later at 12:45 AM, just 25 minutes after he reportedly dropped off a group of passengers who were apparently unaware that their Uber driver was a wanted man.

A passenger jokingly asked Dalton if he was the shooter

One of the men in the car during this last fare told Michigan's Wood TV news that he jokingly asked Dalton if he was the shooter, having heard about the attacks earlier in the night, but received a negative answer. Another Kalamazoo man said that an Uber driver took him on a terrifying ride at around 4.30 PM on Saturday, around 90 minutes before the first attack took place. "We were driving through medians, driving through the lawn, speeding along and when we came to a stop, I jumped out the car and ran away," Matt Mellen told WWMT News. In a now-deleted Facebook post, Mellen's fiancée posted a picture of a man that looked distinctly like Dalton, and warned other Kalamazoo residents about getting into the Uber driver's car.

An Uber source told the Washington Post that Dalton worked as a driver for the company, and the company has released a statement in which it said it "was horrified and heartbroken" at the "senseless violence" in Kalamazoo. Joe Sullivan, Uber's chief security officer, said the firm had reached out to police to co-operate in any way it can. The incident is likely to raise more concerns about Uber's background security checks, an issue the company has taken criticism for before. Last year a lawsuit was brought against the company after it hired 25 drivers in New York and Los Angeles with criminal records, in which prosecutors argued that despite expanding its background checks in 2014, Uber was still misleading customers about their inspections into their drivers' histories.