Uber will not be held criminally liable for a crash last year in which one of its self-driving cars struck and killed a pedestrian in Tempe, Arizona the first accident of its kind.

Yavapai County Attorney Sheila Polk wrote in a letter Tuesday that there was no basis for criminal liability for the Uber corporation arising from this matter but referred the conduct of the person behind the wheel to local police to obtain more evidence.

The crash took place last March when one of Ubers autonomous SUVs, traveling about 40 mph, struck 49-year-old Elaine Herzberg, who was walking her bike across a dark section of a street. Software on the vehicle recognized her as a pedestrian but didnt stop the SUV because a system to automatically apply brakes was deactivated to reduce the potential for erratic vehicle behavior, according to a report from the National Transportation Safety Board.

It was the first known death of a person in America from a self-driving vehicle.

Uber said the person behind the wheel, Rafaela Vasquez, was expected to act in such situations. But video footage from inside the SUV showed she was distracted at the time and investigators later said she was watching an episode of The Voice on her phone at the time of the accident.

Vasquez said at the time that she didnt see Herzberg and that Herzberg came out of nowhere. Polks office has returned the case to the Maricopa County Attorneys Office to determine if Vasquez will face any criminal charges, which could include vehicular manslaughter , according to Reuters.

This Office has concluded that the collision video, as it displays, likely does not accurately depict the events that occurred. We therefore recommend that the matter be furthered to the Tempe Police Department to obtain additional evidence, Polk wrote Tuesday.

Herzbergs family filed a $10 million lawsuit against the city last month, accusing officials of paving a section of the road to look like a crosswalk.

[The site of the accident] has a brick pathway cutting through the desert landscaping that is clearly designed to accommodate people to cross, the claim reads. AZ Central notes that the city tore out the pathway last fall and replaced it with landscaping.

Uber stopped testing its self-driving vehicles in Arizona after the accident but has focused on a smaller program in Pittsburgh. Each car in that test had two drivers inside to take over in case of emergencies, and no passengers were inside during the rides. The company also said the cars wouldnt go faster than 25 mph.