Hmm, I shall have to have laptop to hand when I next hear it's (Police) drone as it very distinct, see if it shows up or not.
interesting FR doesn't show 'everything' as an amateur I'd not considered their coverage till now so that's worth remembering,
for the record I'd imagine at least that local forces of Law & Order would have use of fairly new equipment and a quick search on net reveal aircraft in use over this region; G-EMID
at least I think that's the current machine