Uber is once again under fire for how it conducts background checks.
The Colorado Public Utilities Commission (PUC) fined Uber $8.9 million on Monday for allowing drivers with "disqualifying" criminal or motor vehicle offenses to drive for the company. Some of them did not have valid licenses and others used fake names, the PUC revealed.
In one case, the company hired a driver in Colorado who was previously an escaped felon. He passed a background check by using an alias.
Related: What we know (and don't know) about Uber background checks
In a notice issued by the commission, there were violations listed for 57 Uber drivers over the last year and a half who shouldn't have passed a background check, PUC said.
Uber was fined $2,500 per day for each day a disqualified driver worked.
Earlier this year, the commission's staff began an investigation after the Vail Police Department notified them about an Uber driver accused of assaulting a rider.
When comparing records provided by Uber to information from court databases, PUC staff found Uber had approved drivers with previous felony convictions, major moving violations such as DUIs and reckless driving, and found "numerous instances" of people driving with suspended, revoked or cancelled driver's licenses.
"We have determined that Uber had background check information that should have disqualified these drivers under the law, but they were allowed to drive anyway," PUC director Doug Dean said in a statement. "These actions put the safety of passengers in extreme jeopardy."
Related: More than 8,000 Uber and Lyft drivers fail Massachusetts background check
Uber said it was made aware of the fine when PUC published its press release.
"We recently discovered a process error that was inconsistent with Colorado's ridesharing regulations and proactively notified the Colorado Public Utilities Commission," an Uber spokeswoman said in a statement to CNN Tech. "This error affected a small number of drivers and we immediately took corrective action."
Uber has over 13,000 active drivers in Colorado.
Uber mostly conducts digital background checks via a startup called Checkr. The startup screens applicants by using Social Security numbers to identify associated addresses. It then reviews driving and criminal histories in national, state and local databases. Those databases include the U.S. Department of Justice National Sex Offender Public Website and ones that flag suspected terrorists.
Checkr is bound by the Fair Credit Reporting Act, a federal law that regulates how reporting agencies use a person's information.
However, a source familiar with Checkr previously told CNN Tech that Uber makes the final decision on whether to hire a driver based on Checkr's screening results.
Uber said Colorado's laws are different from ride-sharing laws in other states. For example, a driver convicted of a felony for crimes such as trespassing or forgery would not be allowed to drive with Uber or another ride-sharing company in Colorado.
Colorado's investigation found that 12 Uber drivers had felony convictions; 17 had major moving vehicle violations; 63 had driver's license issues and three had interlock driver's licenses, which are needed after recent drunk driving convictions.
An ignition Interlock is a device installed in a car that requires a breath sample before the engine can start.
