Photo: Paul Chinn / The Chronicle Photo: Paul Chinn / The Chronicle Photo: Gene J. Puskar, Associated Press Photo: Liz Hafalia / The Chronicle Photo: Liz Hafalia / The Chronicle 2017

Lyft is scrambling to reinforce its background checks after revelations that an undocumented immigrant who has been charged with serial rape had worked as a Lyft driver.

Orlando Vilchez Lazo, 37, whom police have dubbed the “Rideshare Rapist,” posed as a ride-hailing driver in order to kidnap and rape four women as they left San Francisco bars and nightclubs, according to San Francisco authorities who said he had stickers from a major ride-hailing company on his car — a tactic that presumably helped with the deception.

Although there are no allegations that Vilchez Lazo was giving rides for hire when the rapes occurred, Lyft confirmed that he had worked for the company and said that he has now been deactivated, its word for terminated. The rapes occurred from 2013 to this year.

“Individuals who drive for Lyft must be eligible to work in the United States,” spokeswoman Kate Magolis said in a statement. “In this circumstance, this person fraudulently represented themself. Together with our background check provider, we are adding enhanced detection processes that will apply to all new and existing applicants.”

The nature of the fraud Lyft is claiming is unclear, since the company will not provide details.

On Thursday, Vilchez Lazo pleaded not guilty in San Francisco Superior Court.

Lyft didn’t answer questions about what changes it is making. It and Uber use public records to vet drivers. Both companies rely on the same provider: San Francisco’s Checkr. (Lyft recently switched to Checkr, which was not the background check provider when Vilchez Lazo was vetted. It isn’t commenting on other providers, but New York’s Sterling Talent Solutions confirmed that it previously worked for Lyft without specifying the dates.)

Photo: Liz Hafalia / The Chronicle 2017

Both ride-hail companies fiercely resist fingerprint checks, which are cumbersome, expensive and have a reputation for unfairly singling out minorities. However, biometric screening could make life harder for fraudsters.

“What’s key in this story is that (the rape suspect) must have used someone else’s identity,” said Harry Campbell, a Los Angeles ride-hail driver who runs the Rideshare Guy blog and podcast. “The scary part is that there doesn’t have to be an in-person meeting between a potential new driver and a representative from either (Lyft or Uber). You can apply and get approved online without ever seeing anyone face to face.”

The ride-hailing companies have each applicant submit a selfie that they compare to the driver’s license photo. Uber goes further, asking drivers to take a selfie at random times after they have started working. The company compares the selfies to the driver’s profile to verify that the same person who signed up to drive is still behind the wheel.

California law requires Lyft, Uber and other ride-hailing services to conduct local and national criminal background checks for drivers, who must provide a Social Security number and a valid driver’s license. The companies also check potential drivers’ Department of Motor Vehicle records for violations, some of which can disqualify them. Drivers must show up-to-date car registration and valid insurance with their name on the policy. They do not have to own the cars they drive.

Both do these checks annually for all U.S. drivers. Uber recently added ongoing criminal background checks.

Both are required to use the DMV’s Employer Pull Notice program, which alerts employers of workers’ traffic violations as they occur.

Evading a public-records background check isn’t easy, said Brad Landin, president and chief compliance officer for Novato’s Employment Screening Resources, which does background checks for employers in all 50 states.

“If someone is bound and determined, they could probably circumvent it by acquiring a Social Security number, adopting a name, somehow creating a history, employment, using friends as (pseudo) employment references — putting together a whole background,” he said.

That type of elaborate ruse is fairly rare, he said. However, simply using another person’s Social Security number is common among undocumented people. Likewise, getting a fake driver’s license is relatively easy, as teenagers seeking alcohol have learned.

But a thorough background check should uncover such deceptions, Landin said.

While he doesn’t know specifics about Lyft’s checks, an industry best practice is to use E-Verify, a website where employers check Social Security Administration and Department of Homeland Security databases, Landin said. “It identifies any discrepancy and then requires the applicant to rectify that in person,” he said. “It’s the most definite way to identify” people who cannot legally work in the U.S. However E-Verify can only be used by companies hiring employees. Lyft and Uber drivers are independent contractors so neither company uses E-Verify.

The next step in a thorough probe is a comprehensive public-records search, including all counties where an applicant has lived and worked, he said. That is part of both Lyft and Uber’s screening process.

Biometric checks, such as fingerprints, are not as all-encompassing as many people believe, Landin said. FBI records contain only about 65 percent of criminal records. Only half show the outcome — whether an arrest resulted in a conviction, a not-guilty finding or if the charges were dropped. That means someone who was arrested without charges being filed can still turn up in the databases. Advocates say fingerprint checks discriminate against people of color, who are disproportionately targeted by the police.

Boston startup Safr bills itself as a more female-friendly ride-hailing company. CEO Syed Gilani said it has mentors personally meet all drivers in addition to doing public-records background checks. The service will start operating in the Bay Area in the next few weeks.

“It’s very, very important to us to make sure our on-boarding process is human-powered,” Gilani said.

Carolyn Said is a San Francisco Chronicle staff writer. Email: csaid@sfchronicle.com Twitter: @csaid