I actually raised this issue here years ago when I made this damn account and I actually had people telling me this information and topic had no place in this section of the forum. I respectfully beg to differ.
BTW, you can of course ask a cop if it is ok that you record him / her and if they say yes (good luck with that!), then you can certainly continue to record. You know how when you call into your auto insurance co's (or any corporate 800#), they always have that little recording that says, "for quality assurance, this call may be monitored or recorded". They MUST tell you this, otherwise it's felony wiretapping in 12 States. If you tell the CSR that you do NOT consent to being recorded or monitored, they MUST NOT record the conversation (at least by law..). And if you continue with no objection, that is your defacto consent....things staring to click now?