Two party consent doesn't matter here. The federal courts have consistently upheld that it is one's first ammendment right to record public officials in the performance of their duties. As a member of the public, you are permitted to record your interactions with police.
Now, could it still end badly? Sure. If they are willing to break the law for a bribe, then why not take it further if they find out you are recording.
Local police have been noticeably resistant to rules allowing recording. A large fraction of the civil rights violations documented by Amnesty International against BLM protestors were exactly against people who were only recording what was going on.
Therefore no matter how much you might be within the right, I would personally not be willing to record the police unless it was under the direction of another police force that was ready to barge in.
Secret recording protip: get the target to identify themselves in a unique manner. Such as affirmative responses when called by their name and nickname. A certain action others can corroborate such as a triple high pitched sneeze. Or sounds that are unique to them such as a cell phone text message chime. Combine the above for maximum impact.
Present this to a lawyer and watch them work their magic.
I currently have a case where a trooper lied to a judge to conceal exculpatory evidence and it is documented. I emailed a few firms for a free consultation. So far I have not found a civil lawyer willing to take it. Decided to email the ACLU too, so we'll see if we hear back from them.
You should listen to the reason why all of those civil lawyers are not willing to take it. Listen very carefully. I would advise you to believe the word of several people telling you why it’s not possible...
No one has told me it's not possible. I have a trooper and a lawyer from a other area of law telling me it sounds like a good case. The lawyers that I have contacted only a few days ago simply haven't responded yet.
And do you think it's likely they'll be 'on duty' when this discussion occurs?
You're really trying very hard to downplay the risk of gathering this evidence. If you are discovered and you gathered evidence, you might have that evidence confiscated or you might just be dead. If you are discovered but didn't manage to get the evidence, you might be charged with wiretapping. (Or they might just kill you anyway.) Even if all works out in the end, you're looking at a legal battle. (Most people don't want to be the one fighting a case that sets precedence even if federal courts largely seem to rule in their favor.) And all that struggle is for evidence that might not even convince anyone to start an investigation and/or may not be admitted to court.
Now, could it still end badly? Sure. If they are willing to break the law for a bribe, then why not take it further if they find out you are recording.