Always talk to the police -- AFTER GETTING IMMUNITY. Basically first if they ask you anything, say "I will happily comply with any questioning if you give me immunity in writing to this case or anything resulting from my answers."
The cop who gave that presentation even mentioned getting an IRS call, and said that, they never called back.
Point is, ask for immunity.
No no no, a thousand times no. Immunity is a very nuanced thing that, in the US especially, is beyond the understanding of laypersons. Talk only to and through YOUR lawyer. Don't go anywhere near any talk of "immunity" without several days to discuss the matter with paid legal counsel.
Federal means that subnational units have some limited sovereignty, versus unitary where only the toplevel government has sovereignty.
IANAL, but if you're arrested, just ask for a lawyer. Don't try to play weird games like asking for immunity. The police have played them way more than you, you don't know the legal system and you will probably lose.
FTFY ;)
A cop can't grant you immunity, and most people wouldn't know what it meant if you did have an immunity agreement.
Obviously different if your lawyer says that requesting immunity might work, probably because you're knee deep in someone else's mess and their experience tells them that prosecution will be far more interested in your testimony against them than stuff you might need to admit to.
The bigger lesson was not to ask for immunity, but to refuse to say anything without your lawyer present. (...and then, obviously, to only say things if your lawyer advises you to do so.)
Some of these might not really be de jure OK for the cops to tell you, but would you want to rely on a court upholding that?
( https://reason.com/2011/03/08/tennessee-cops-posed-as-a-defe... in this case, the trial court even allowed it-- it had to get overturned on appeal )
There is a whole subreddit (/r/legaladvice) where the moderators are all (almost all?) law enforcement officers, where they remove good information from actual attorneys and promote bogus "cop law" that is highly detrimental to the interests of the users.
https://slate.com/news-and-politics/2017/10/suspect-asks-for...
The worst case outcome is that police officer testifying to a jury that you agreed to answer questions about a crime once you had immunity.
This is a terrible plan that ends terribly for you. Smart people think they'll be able to logic and reason themselves out of the crosshairs of the criminal justice system. But they're playing a game they don't know how to play and the odds are stacked for the house.
“Officer, was there anything strange about the defendants response to finding out his ex-roomate had been murdered?”
“Well he immediately asked for immunity to cover his actions in the crime”
Never talk to the police, refer them to your lawyer.
And given that cops can legally lie, that promise of immunity seems empty.
Either they go do the legwork or you avoid random liability for whatever you might have said.
When your lawyer asks for immunity it can’t be used against you in court. If you ask, it almost certainly will.
I won't trust myself to handle legal processes, and I certainly won't be able tell if the police had forged a document for me to sign.
Why? Because if you end up in front of a jury, that police officer is going to testify to that jury that you said "you'd tell them anything when they granted you immunity", a truthful statement, and the jury is going to fill in whatever gaps the prosecutor suggests they fill in.
If you are in police custody you ask for nothing from the police. You tell them that you are remaining silent until your lawyer arrives. And then you shut up.
Police can and do lie to people to get them to confess to stuff. "We'll go easy on you, we promise", or "this is off the record, you can tell us anything now" etc. So what stops them from saying something like "sure, you got immunity, now let us in".
The IRS would never call you in a situation where that would matter, and in fact they try very hard to make that public since fake IRS enforcement calls are a very common scam.
So the cop was either lying to you, or was caught in a scam and accidentally scared them off by showing they weren't going to immediately buckle under, without even realizing it was a scam.
Ask for a lawyer, not immunity. And take legal advice from your lawyer, not from cops who, as a class, have neither the knowledge nor the motivation to give good advice.