The Waymos still have all their normal driver controls. There is a process where law enforcement can enter the vehicle, call Waymo and verify their law enforcement status, and then switch the vehicle into manual mode and drive it as normal.
Here is their instructions for law enforcement in the Waymo Emergency Response Guide:
Do the even have physical controls to do that at this point?
I’ve never been in one so I don’t know how different they are from normal cars today.