The police are interrogating a 16-year old murder suspect. The kid is in a gang, and he's worried that if his gang friends find out that he's said anything to the police, they'll kill him in prison. The 16-year old tells the officer:
"You’d be surprised all the things they know, man. Everybody [who] snitches, they get killed in prison, sooner or later. They know, they know somehow. They find out. That’s, that’s, that’s how bad those people are. And you say you’re not gonna say nothing. Someone’s gonna find out no matter what. What I just said right now, is gonna get me killed sooner or later. By my own people, man. I know you’re gonna tell someone else."
A legitimate fear, to be sure.
But fear not. We can trust the police. Here's what the officer tells the 16-year old:
“[Defendant]: If I talk, nobody’s gonna know?
Detective: It’s gonna be between us, bro. It’s between us right here.
[Defendant]: Promise?
Detective: I promise. It’s with us right here. Okay? I do have to write everything down, eventually, because I gotta type, uh, for, like, ever. But just be honest, brother.”
Don't worry. It's between us right here. I promise.
Oh, and I also have a beautiful bridge in Brooklyn I would like you to see.
I'll not further complicate things by adding the stuff about the 16-year old repeatedly saying that he wanted to pee but the officer not letting him. That'd be piling on.
The Court of Appeal affirms the conviction notwithstanding the promises on the basis of wiggle room in the officer's representations to the kid. So, yeah, the officer repeatedly promised that whatever was said would stay "between us right here". But he also said that he would eventually "have to write everything down." A caveat that I'm certain the 16-year old understood meant that the "promise" had absolutely no significance and that any admission would be played out in front of his gang member friends in a public trial. Because 16-year olds are incredibly, incredibly smart. Especially 16-year old gang members.
The Supreme Court allows officers to deliberately lie to suspects. So that's the law. But cases like this demonstrate that there's nonetheless a downside -- both public relations and otherwise -- to this permitted (and routine) practice.
Once everyone learns, as they should, that you can't trust a word that a police officer says to you -- even when (as here) they expressly say "I promise" -- that realization may have profound significance for future interactions between the police and the citizenry.