Prosecutors determined Tuesday that Uber won't be held criminally liable for the death of a pedestrian in Arizona last March. One of the ride-hailing company's autonomous vehicles struck Elaine Herzberg, 49, who later died from her injuries.

"After a very thorough review of all the evidence presented, this Office has determined that there is no basis for criminal liability for the Uber corporation arising from this matter," Yavapai County Attorney Sheila Sullivan Polk said in a letter.

Uber declined to comment.

Polk called for further investigation into a dashcam video of the collision and of what the backup driver, who could face vehicular manslaughter charges, would've been able to see during the accident. Polk wasn't immediately available for comment.

Autonomous vehicles have a backup driver to intervene in case of emergencies. Police told Reuters that the driver in this incident was streaming an episode of The Voice at the time of the accident and not watching the road.