In view of the earlier comment about compatibility.....
To play the full police role you need the full kit, focussed on the area you are operating over.
Does that mean the NPAS craft will all have to be tweaked to a common standard to be truly National or is it simply the flick of a switch for the role equipped airframes to comply with local needs?
I am aware there is a problem with the downlink [ECS or not ECS].