Surely, a police officer will find it difficult to torture someone with an ADS system. You can hardly drive around town gunning people down with one of these mounted on the back. Misuse of the ADS system by the police requires three things: the (expensive and therefore difficult to authorise use of) ADS system, the cooperation of your colleagues (good luck firing a vehicle-mounted pain beam without alerting your friends) and the intent to cause pain to innocent people. As I have said, it is much easier to simply beat someone up than to get hold of the department pain gun and aim it at someone.
Now, in any case, the non-lethal settling of conflict is always preferable to causing death. That's why jails were invented. If a riot breaks out, set this to a high level and sweep across crowd. If you can pull it off fast enough, that's an entire crowd on its knees. If the riot is armed, say a couple of them have AK-47s, and a couple more have grenades, of course they are a threat. Shooting them would work, sure, but you'd have dead people everywhere, because panic would break out and you would be hard-pressed not to hit an innocent person. Beam them instead. They'll be on the ground in a second, and at least in the case of the AK-47, threat neutralized. Without taking a life.
And if you're thinking soldiers or police will be indiscriminate with this thing, remember that all police officers have to be tasered several times before they can have one.