Tesla is facing a criminal probe over its claims about its driver assist technology, according to Reuters. The US Department of Justice launched an investigation late last year following more than a dozen crashes, some of which were fatal, involving the company’s Autopilot feature.

Tesla CEO Elon Musk has been promising actual driverless cars are coming since 2016 — a promise he has yet to deliver. He’s gone from saying that Tesla will have 1 million robotaxis on the road by the end of the year to 1 million people in the FSD beta program, which are wildly different things.

Tesla vehicles today come standard with a driver-assist feature called Autopilot. For an additional $15,000, owners can buy the FSD option, which Musk has repeatedly promised will one day deliver fully autonomous capabilities. But to date, FSD remains a “Level 2” advanced driver-assistance system, meaning the driver must stay fully engaged in the operation of the vehicle while it’s in motion.

Loved by fans and loathed by safety advocates, the FSD software has gotten Tesla in a lot of hot water recently. The National Highway Traffic Safety Administration is currently investigating 16 crashes in which Tesla vehicle owners using Autopilot crashed into stationary emergency vehicles, resulting in 15 injuries and one fatality. The probe was recently upgraded to an “Engineering Analysis,” which is the second and final phase of an investigation before a possible recall.

The company has been accused of false advertising by regulators and sued by customers for allegedly misleading them about the capabilities of their vehicles. But FSD is also crucial to Musk’s vision to portray Tesla as a leader in AI and robotics. And Musk has largely avoided any serious consequences in his pursuit to be at the bleeding edge of technology.

A Justice Department investigation represents a higher degree of scrutiny since it carries the risk that Tesla or its executives will be charged criminally. According to Reuters, federal prosecutors in Washington and San Francisco are examining whether Tesla misled consumers, investors, and regulators by making unsupported claims about its driver assistance technology’s capabilities.