But I wonder if the decision requires the "robot" to have a human controller or can the police unilaterally expand the kind of devices they use to include more autonomous ones?
In the USA, if I understand it correctly, it seems there is a lot of case law establishing criminal or civil liability for autonomous mechanical devices that kill or injure someone - Typically traps like tripwired guns, so it would be interesting to see how it applies to autonomous robots having some degree of "perception" and "judgement"
Do those cases apply to the police though? Qualified immunity is basically a separate, non-overlapping set of case law for police liability that also coincidentally almost always rules that they have none.