The safety driver behind the wheel of a testing self-driving Uber car in Tempe, Arizona, US, was streaming a live video show on her smart phone until roughly the time of the fatal crash, according to a police report that deemed the March 18 incident "entirely avoidable."

A report by the Tempe Police Department said the driver, Rafaela Vasquez, repeatedly looked down instead of forward on the road, glancing up a half second before the car hit Elaine Herzberg, 49, who was crossing the street at night.

The report said police concluded the crash, which has dealt Uber Technologies Inc. a major setback in its efforts to develop self-driving cars, would have been "entirely avoidable" if Vasquez had been paying attention.

Vasquez could face charges of vehicular manslaughter, according to the report, which was released late on Thursday in response to a public records request.

She could not immediately be reached for comment.

Police obtained records from Hulu, an online service for streaming TV, video shows and movies, which showed Vasquez' account was playing the TV talent show "The Voice" for about 42 minutes on the night of the crash, ending at 9:59 p.m., which "coincides with the approximate time of the collision," the report said.

Police submitted their findings to local prosecutors, who will make a determination on whether to file criminal charges. The Maricopa County Attorney's Office referred the case to the Yavapai County Attorney's Office because of a conflict.

A spokeswoman for the Yavapai County Attorney's Office said on Friday that "the matter is still pending review. We do not have a projected timeline for a decision."

The Uber car was in autonomous mode at the time of the crash, but the company, like other self-driving car developers, requires a back-up driver inside to intervene when the autonomous system fails or a tricky driving situation occurs.

Vasquez looked up just 0.5 seconds before the crash, after keeping her head down for 5.3 seconds, the Tempe police report said. Uber's self-driving Volvo SUV was traveling at just under 71 km/h.

"We continue to cooperate fully with ongoing investigations while conducting our own internal safety review," an Uber spokeswoman said. "We have a strict policy prohibiting mobile device usage for anyone operating our self-driving vehicles. We plan to share more on the changes we’ll make to our program soon."

Last month, the Uber spokeswoman said the company was undergoing a "top-to-bottom safety review," and had brought on a former US federal transportation official to help improve its safety culture.

Police said a review of the video from inside the Volvo showed Vasquez was looking down during the trip, and her face "appears to react and show a smirk or laugh at various points during the times that she is looking down." The report found that Vasquez "was distracted and looking down" for close to seven of the nearly 22 minutes prior to the collision.

Tempe Police Detective Michael McCormick asked Hulu for help in the investigation, writing in a May 10 email to the company that "this is a very serious case where the charges of vehicle manslaughter may be charged, so correctly interpreting the information provided to us is crucial." Hulu, the American entertainment company that provides TV, movies and livestreaming online, turned over the records on May 31.

According to a report last month by the US National Transportation Safety Board, which is also investigating the crash, Vasquez told federal investigators she had been monitoring the self-driving interface in the car and that neither her personal nor business phones were in use until after the crash. That report showed Uber had disabled the emergency braking system in the Volvo, and Vasquez began braking less than a second after hitting Herzberg.

Herzberg, who was homeless, was walking her bicycle across the street, outside of a crosswalk on the four-lane road, when she was struck by the front right side of the Volvo.

The police report faulted Herzberg for "unlawfully crossing the road at a location other than a marked crosswalk."

Uber shuttered its autonomous car testing program in Arizona after the incident, and says it plans to begin testing elsewhere this summer, though in some cities it will have to first win over increasingly wary regulators.

(Top image: A video grab made from dash cam footage and released by the Tempe Police Department shows the moment before the collision of ride-sharing Uber's self-driving vehicle and a pedestrian in the city of Tempe, Arizona, US, March 18, 2018. /VCG Photo)‍