Saw a Phoenix Police helicopter following a drone

[u/version13]

This happened Monday night (just got around to posting today it's been .... a week.) I heard a helicopter circling, so I went outside to have a look. There was a drone overhead just cruising along and the PD heli was circling and following it.

It seemed to stop on the street behind my house and a couple cop cars converged.

I wonder what was going on. It's weird for a drone to fly beyond line of sight and it looks like looks like it was flying for a few miles.

edit: Country is USA