They are not hiding anything, You can FOI the tapes and they will give them to you so you can sit and listen to see if they are hiding anything.
The only thing Encryption does is keep you from listening to them live, it does not change the ability to listen to them later to catch the bad things they are doing
Please do explain how it's so easy, when, in order to submit a FOIA request, you must request the exact details of what you want (not sure if you've done FOIA requests)
For example - a very rough but simple request, in case you aren't familiar,
"I am requesting unedited and full-resolution electronic copies of all photo, video (including, but not limited to dashcam, bodycam, and cell phone video), and radio traffic relevant to the arrest of John Doehammer, on July 4th, 2003, to be transferred to me over the internet. This includes any of the previously mentioned records leading up to the arrest, during and up to booking."
You can't just say,
"I request a copy of all your radio traffic on July 4th, 2003"
That's not how it works.
So your argument is moot, because you can't possibly know of wrongdoing if you didn't hear/see it, so how would you know to request it?
Also, you sometimes have to wait
years before you can actually receive the requests (case closed, open?) Forget all of the requests that get denied wrongfully. Unless you have the money to sue for them, you arent getting them, no matter how blatantly wrong the denial may be.
It sounds like someone told you "encryption doesn't make any difference, people could just submit FOIA requests of whatever they want" and you took it at face value. That's not the case.