Uber, whose application is being used here, has fought against measures such as fingerprint scanning that some believe would elevate its background checks to the level of the taxicab industry and law enforcement (Andrew Caballero-Reynolds/AFP/Getty Images)

Saturday’s mass shooting in Kalamazoo, Michigan, was the latest in a string of incidents over the past few years that have stoked concern over Uber’s vetting process for drivers.

The company confirmed on Sunday that suspect Jason Brian Dalton, 45, of Kalamazoo, was one of its drivers. Ninety minutes before he opened fire on random bystanders and restaurant patrons in the southwestern Michigan city, he picked up a resident for an Uber ride. His driving was so erratic that the passenger cut the trip short and dialed 911. Now, investigators are looking into whether Dalton picked up and dropped off passengers after the shooting began.

But even before Dalton opened fire on Saturday, the company’s vetting process was drawing scrutiny in the legal system and locales across the globe. Uber has fought against measures such as fingerprint scanning that some believe would elevate its background checks to the level of the taxicab industry and law enforcement.

Just this month, Uber said it would pay $28.5 million in the settlement of two lawsuits that accused the ride-hailing firm of misleading passengers about its safety. The lawsuits claimed that while Uber used phrases such as “safest ride on the road” and “industry-leading background checks,” it did not fingerprint-scan its drivers or check their status on the national sex-offender registry.

In the case of the Kalamazoo shooter, it was unclear how a background check would have helped. Kalamazoo Public Safety Chief Jeff Hadley said the suspect in Saturday’s shooting did not have a criminal record. An Uber spokeswoman directed a reporter to a company blog post that outlined its background check procedure.

In other cases, the company’s screening process has failed to weed out would-be criminals. The ride-hailing service was banned in New Delhi in 2014 after a driver was charged with rape. Police there questioned an Uber official about the company’s screening process, saying simple security measures such as fingerprinting and conducting a background check on the accused driver were not conducted. Police said the driver had been acquitted of rape charges in a 2011 incident.

A year before the New Delhi incident, a 6-year-old girl was struck and killed by an Uber driver in San Francisco who had been convicted of reckless driving in Florida.

And the safety-related lawsuit filed in California includes a complaint that one Uber driver had been convicted of second-degree murder in 1982, before being paroled in 2008. The suit says the man applied to be a driver using a different name than one listed in court records, according to the New York Times.

Uber declined to comment Sunday on its confidence in its screening process in the wake of the Kalamazoo shootings.

According to the company’s blog post on driver screening, background checks are conducted by Checkr, a San-Francisco-based firm that is nationally accredited in professional screening. Drivers provide identifying information inclduing their social security numbers and license information, and Checkr searches sex offender and criminal registries. If a potential criminal record is found, the company sends an employee to review the record in person at a courthouse if the record cannot be pulled digitally. Being listed on a sex offender registry disqualifies a potential driver entirely. DUI, drug-related convictions, reckless driving, violent crimes and sexual offenses disqualify drivers if they were convicted within seven years of applying, Uber says.

The blog post also includes a lengthy critique of the fingerpint scanning process that taxi drivers in most of California undergo. That process involves taking a person’s fingerprints to run them through FBI and state databased looking for a match, Uber says. San Francisco District Attorney George Gascón, who jointly filed the lawsuit alleging Uber improperly screened drviers, said in a 2014 news conference a background check that does not include fingerprint scanning is “completely worthless.”

Rich Robinson, a Silicon Valley-based attorney and political consultant who has written critically of Uber’s screening process, says its cars should be regulated just like taxis.

“The fact is that they sign up people sort of willy-nilly ... and those people become drivers for the general public, and the general public doesn’t know who they’re getting,” he said. “Ultimately Uber is a taxi-cab company. That’s what they are. And basically they should be regulated and treated like a taxi cab company.”

Uber, however, contends that the fingerprint-scanning system is flawed. Its blog post said that in 2014, at least 600 people who previously drove taxis in San Diego, Los Angeles and San Francisco, cities that require “Live Scan” fingerprinting failed its background check. That meant they could not drive for Uber but may be able to continue driving taxis, Uber said, though it did not specify it they had been booted from the taxi system as well.

Uber concluded in its post that no system is perfect.

“Of course, the background check system that Uber and other ride hailing companies use is not 100% accurate either. For example, a potential driver may have a stolen or fraudulent identity, an illegally obtained but valid social security number that conceals his or her true identity, or he or she may have been convicted of a crime outside the background lookback limits permitted by state law.”

Edward Davis, a former Boston Police commissioner who serves on Uber’s Safety Advisory Board, said the shootings, while tragic, were the type of “psychotic episode” that could not be predicted by an employee screening. He said the issue could potentially be chalked up to factors such as mental health or the ease of access to firearms, but a background check would not have been an effective predictor of Dalton’s behavior.

“To try to forecast this, to try to identify someone who might act this way, whether they be an Uber driver or a taxi driver or in any process, it’s just really difficult,” he said. “To be able to see into the future is very difficult.”

He conceded that, while the shooter did not have a criminal record according to authorities, a thorough background check could turn up other indicators that would preclude an employee’s hiring.

“There are red flags that are raised in background checks all the time that don’t raise to the level of criminal activity,” Davis said.

He added that Uber’s five-star rating system could have been a way of identifying concerning behavior, if passengers reported seeing it. An Uber spokeswoman on the phone call declined to reveal Dalton’s driver rating or detail any feedback he had received from passengers.