The human back-up driver in an autonomous Uber car was streaming television show The Voice just before the vehicle struck and killed a pedestrian, according to a report in the US.
The Arizona Republic said the driver was streaming the musical talent show on Hulu in the moments before the crash on a darkened street in the Phoenix suburb of Tempe.
Police obtained records from Hulu with a search warrant show that the streaming to one of the driver’s mobile phones ended at 9.59pm on March 18, while the crash occurred at about 10pm.
The newspaper received the more than 300-page report from Tempe police late on Thursday.
Elaine Herzberg, 49, was struck as she crossed a darkened road in the middle of a block. It was the first fatal crash involving a self-driving vehicle.
Prosecutors are considering charges against the driver, 44-year-old Rafaela Vasquez.
A previously released video of the crash showed Vasquez looking down just before the crash. She had a startled look on her face seconds before the impact.
The National Transportation Safety Board, in a preliminary report issued last month, said the autonomous driving system on Uber’s Volvo XC-90 SUV spotted Ms Herzberg about six seconds before hitting her, but did not stop because the system used to automatically apply brakes in potentially dangerous situations had been disabled.
The system is disabled while Uber’s autonomous cars are under computer control, “to reduce the potential for erratic vehicle behaviour”, the NTSB report said.
Instead of the system, Uber relies on the human back-up driver to intervene, the report said, but the system is not designed to alert the driver.
Uber pulled its self-driving cars out of Arizona the day before the NTSB report was released, eliminating the jobs of about 300 people who served as back-up drivers and performed other jobs connected to the vehicles.
The company had suspended testing of its self-driving vehicles in Arizona, Pittsburgh, San Francisco and Toronto while regulators investigated the cause of the crash.
Arizona governor Doug Ducey prohibited Uber from continuing its tests of self-driving cars after Ms Herzberg was hit.
Tempe police also released blurred video from the responding police officers’ body cameras, and one caught a conversation with Ms Vasquez while she was seated behind the wheel, according to the newspaper.
“The car was in auto-drive,” she said to the officer. “All of a sudden… the car didn’t see it, I couldn’t see it. I know I hit her.”
The report says police initially determined that Ms Vasquez was not impaired after giving her a field test.
Several days after the crash, police got search warrants for her two mobile phones and served them on three companies: Hulu, Netflix, and Google which owns YouTube.
Hulu provided records showing that Vasquez was watching The Voice just before the crash, the newspaper reported.
In the lengthy report, Tempe police wrote that Ms Vasquez “appears to be looking down at the area near her right knee at various points in the video”.
Sometimes her face “appears to react and show a smirk or laugh at various points during the times that she is looking down.
"Her hands are not visible in the frame of the video during these times”.
A detailed analysis of video from inside the SUV shows during 11.8 miles travelled before the crash, Ms Vasquez looked down 204 times towards her right knee, according to the report.
Of the nearly 22 minutes that elapsed during that distance, she was looking down for six minutes and 47 seconds, the newspaper reported.
“This crash would not have occurred if Ms Vasquez would have been monitoring the vehicle and roadway conditions and was not distracted,” the report said.
A crash report also indicated that the self-driving vehicle was travelling too fast for the road conditions.