The backup driver in the self-driving Uber vehicle that killed a 49-year-old woman in Tempe, Arizona, in 2018 pled guilty to one count of endangerment and was sentenced to three years’ probation on Friday.

Rafaela Vasquez worked as a safety driver for Uber’s autonomous vehicle test program in Arizona. She was behind the steering wheel when her vehicle ran over Elaine Herzberg, who was pushing a bicycle across the street. The crash, which happened on March 18th, 2018, is believed to be the first fatal collision involving a self-driving car.

Prosecutors described Vasquez as “the eyes and ears” of the vehicle, which was operating in autonomous mode at the time of the collision, according to the Arizona Republic. Police alleged that she was streaming the TV show “The Voice” on her phone at the time, but Vasquez claimed she was monitoring the vehicle’s systems and had glanced away from the road at a crucial moment.

Investigators have said the car saw Herzberg but did not automatically stop and that Vasquez did not brake until it was too late. The car detected that Herzberg was crossing the street with her bicycle 5.6 seconds before impact, but even though the system continued to track Herzberg right up until the crash, it never correctly identified her as a human being on the road, nor did it accurately predict her path. The case has raised important questions about how to safely test the new technology and who should be held responsible when something goes wrong.