You have to record them and submit a complaint to Internal Affairs, and half the time the PO is out of bounds because he can get away with it, but not if you covertly record just in case it's needed later.

Could be off your phone, or you could buy any number of hidden or in view cameras like a gopro.

I wouldn't put the camera in his face, but have it mounted as your silent witness. Plenty of phone apps that will record in Stealth mode. where your screen is off and LOCKED, but it's recording.

I have 16 cameras around my house and property, so I speak from a place of ... uh, knowledge.

PS, obviously not all cops are bad, but G.Damn I hate a F-ing Bully...

Happy to report them to I.A. where my complaint will sit in their service jacket for the rest of their Carrier....