I mean, the conviction rate on cops is embarrassingly low. You have body cam footage, cell phone footage, a law abiding citizen's testimony, and they still just get a month suspension. Too frequently we see cops abusing their power and they get a slap on the wrist.

I think there's a pretty wide range of options between "let the DA who needs the cops to lie so he can keep his conviction rate high half-ass his way though the case" and "bring charges literally every time someone wants to bring charges." I think OP was talking more about WHO handles them, rather than whether all of them have merit.