Should police have the capability to take control of driverless cars?

Future: Cop orders driverless car to halt, vehicle obeys and rolls to a stop.

Photocapy

Driverless cars might be the norm some day—sooner than we think. So it's never too early to consider futuristic scenarios of a driverless car world.
There have already been plenty of ethical questions asked, like whether a driverless car should decide who lives or who dies during an accident scenario. One question often posed is whether a driverless vehicle could choose to ram a school bus full of kids or sacrifice the driverless vehicle's occupants during a mishap.

Now the Rand Corp. is thinking about how law enforcement officials should deal with driverless cars. A recent study (PDF) by the group ponders whether a cop should have the ability to remotely control a vehicle to pull it over.
There are a few ways this could happen. For starters, vehicles could have a method for police to take control baked in at the start. Or maybe the police would have a kill switch—one authorized or not. We all know that vehicles are susceptible to hacking, as Ars has reported recently.
Either way, this will become a real-world debate sooner rather than later. The Rand report doesn't come to any conclusions but briefly touches on the future of unmanned vehicles by painting a hypothetical scene that seems scary to grasp but doesn't seem far-fetched at all.

The police officer directing traffic in the intersection could see the car barreling toward him and the occupant looking down at his smartphone. Officer Rodriguez gestured for the car to stop, and the self-driving vehicle rolled to a halt behind the crosswalk.
The officer waved the car on as the oblivious passenger continued checking his email. But he wasn’t oblivious for long. A very human-driven sport-utility vehicle (SUV) barreled through the intersection, forcing the officer to dive for safety and the automated car to brake hard and swerve to avoid a collision.
While Officer Rodriguez called for assistance, an unmanned aerial vehicle on patrol recognized the speeding SUV and gave chase while it transmitted the vehicle’s location to police cruisers. A police cruiser precision immobilization technique (PIT) maneuver forced the SUV off the road minutes later. As officers prepared to swarm the vehicle, one took the man’s photo from a distance, uploaded it to compare against a national repository of mugshots, and quickly produced a high-probability match. The photo, combined with the license plate and vehicle description, helped the system identify an ex-convict who was related to the SUV’s owner, and who had a lengthy rap sheet of armed robbery and reckless driving.
A few moments later, an armed robbery at a nearby gas station crackled over the officers' radios. Surveillance photos from the scene, showing the SUV driver pointing a weapon at the gas station attendant, arrived shortly after the suspect had been safely taken into custody—where he would remain for a very long time.

Slate's Will Oremus notes that driverless cars are programmed to stop at red lights and stop signs and "should also be programmed to stop when a police officer flags them down."
"If a police officer can command a self-driving car to pull over for his own safety and that of others on the road, can he do the same if he suspects the passenger of a crime? And what if the passenger doesn’t want the car to stop—can she override the command, or does the police officer have ultimate control?" Oremus asks.
The Rand report also conceives of police having the ability to order an autonomous vehicle to move.

Or, if the vehicle is unmanned but capable of autonomous movement and in an undesirable location (for example, parked illegally or in the immediate vicinity of an emergency), an officer could direct the vehicle to move to a new location (with the vehicle’s intelligent agents recognizing "officer" and “directions to move”) and automatically notify its owner and occupants.

None of this matters at the moment, but it will soon enough.