An Uber driver in Boston has been charged with raping his passenger — less than a day after the company promised it would "develop more ways ... to ensure the safety of riders."

The driver, 46-year old Alejandro Done, was arraigned without bail in Cambridge, Massachusetts, late Wednesday. Prosecutors allege he told a female passenger she'd need to pay in cash, drove her to an ATM, got in the back with her, locked the car, covered her mouth and sexually assaulted her.

An Uber spokesperson told a local CBS station that this was a "despicable crime," but also said that Done had passed a background check.

Uber is under fire from district attorneys in San Francisco and Los Angeles over its background-check procedure. Lawsuits from the D.A.s allege that the company misrepresents the quality of its background-checking process, and doesn't use fingerprints to verify the applicant — unlike taxi companies, which are required to fingerprint drivers.

The alleged crime comes after it was revealed that two of three sexual-assault incidents reported to Boston police over the past weekend involved Uber drivers. It wasn't yet known whether Done was involved in those incidents.

Done's arrest couldn't have come at a worse time for Uber, given that the company published a lengthy blog post Wednesday titled "Our Commitment to Safety." In it, Uber's new head of global safety, Phillip Cardenas, claimed the company had "built the safest transportation option in 260 cities around the world," and that it conducts "thorough, multi-layered background checks that have resulted in tens-of-thousands of potential drivers being denied the opportunity to partner on the Uber platform."

New safety features were promised. Cardenas added, "We are also investing in ways to provide riders the instant ability to communicate with us and their loved ones in the event of an emergency."

Cardenas discussed improving Uber's "multi-layered" background checks in rather vague, technical terms. He did not mention the option of simply adopting the industry-standard practice of fingerprinting drivers.

Here's what Cardenas did have to say on the subject:

Our Safety Product Team is developing more ways to put technology to work to ensure the safety of riders and drivers in key areas. We are initiating research & development on biometrics and voice verification to build custom tools for enhanced driver screening ... In many places outside the U.S., the infrastructure and complexity of background checks vary significantly. This is of deep concern to us. We are finding solutions in many places that range from polygraph exams that fill gaps in available data to adding our own processes on top of existing screening for commercial licenses – which is what we are undertaking in India. We are exploring new ways to screen drivers globally, using scientific analysis and technology to find solutions ... Of course, no background check can predict future behavior and no technology can yet fully prevent bad actions. But our responsibility is to leverage every smart tool at our disposal to set the highest standard in safety we can. We will not shy away from this task.

After an Uber driver in New Delhi was accused of rape earlier this month, local law enforcement questioned an Uber executive over its background-check procedure, and an official raised the possibility of criminal charges against the company for misrepresenting its background checks.