A couple in California who ran a used car dealership embody consumers’ worst fears about buying used cars. They now face almost 80 criminal charges of grand theft by false pretenses, perjury, filing false documents with the DMV, and twenty counts of unlawfully rolling back a car odometer.

The investigation started in April of this year, when a customer of the used car dealership brought her car to a mechanic with a functioning brain, who noticed that the car appeared to have traveled at least twice as many miles as the odometer indicated.

Department of Motor Vehicles investigators looked into cars that the dealership had sold in the past, noticing discrepancies between auction records for those cars and the current odometer readings.

Wait, though: how do you roll back an odometer when most cars have digital displays now? Despite what my imagination tells me, rolling back the odometer on a used car is not done by driving it for hundreds of thousands of miles in reverse. No, you can’t even apply for that job.

Instead, it’s done by swapping out that part of the dashboard for one with fewer miles from a car in a junkyard. This is not legal, at least not if you plan to sell the car to someone else. It’s also possible to tamper with digital odometers by hacking the software, which investigators say is a more common method.

Court documents say that both members of the couple played roles in the deception: the husband bought the cars at auction and replaced the odometers with parts sourced from junkyards and elsewhere, and the wife was in charge of typing up price sheets based on the cars’ Kelley Blue Book values using the faked mileage.

Antioch Used Car Dealer, His Wife Facing Nearly 80 Charges In Alleged Odometer Tampering Scheme [CBS San Francisco]

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