Cops radio dispatch for everything, dispatch could disable it during their breaks. Simple checks and balances.

This might not be the ideal solution, it's the one that I thought of in 20 seconds of reading your response - which admittedly, I hadn't even considered. But instead of taking this as an absolute solution please take it as the, "maybe we just need to put some thought into things and we could figure out the better solution that doesn't involve an on demand off button" because that is essentially shrugging off the accountability concern most citizens have.