The lights on the SUV didn’t illuminate 49-year-old Elaine Herzberg on Sunday night until a second or two before impact, raising questions about whether the vehicle could have stopped in time.

The crash Sunday night in Tempe was the first death involving a full autonomous test vehicle. The Volvo was in self-driving mode with a human backup driver at the wheel when it struck Herzberg, police said.

The video shows the human backup driver in the SUV looking down until seconds before the crash. The driver looks up and appears startled during the last moment of the clip.