Based on the precedent set by Uber, Waymo will be held financially responsible, but won't face criminal charges. I'd be interested in reading more about the liability insurance coverage Waymo has for its self-driving program, but can't find info anywhere.

Source: https://usa.streetsblog.org/2019/03/08/uber-got-off-the-hook...

For what it's worth, the backup driver in the Uber case was charged with negligent homicide just a few weeks ago.

https://www.theverge.com/2020/9/16/21439354/uber-backup-driv...