
Can police choose not to accept a confession?
I was recently rewatching the Key & Peele Rap Album Confessions skit (https://youtu.be/14WE3A0PwVs?is=\_ZAiWXcQge3WpVPl) and it made me curious about something.
In the skit they claim to have everything they need to prosecute a man for murder, but at the last minute somebody else confesses in order to go to prison in his place. Everybody seems well aware that this is what's happening and the man is the real murderer.
Now I'm not asking if they have enough evidence or anything like that, it's a comedy skit, but I'm focusing in on that one aspect. If there was a situation where the police/DA/prosecution/basically everybody knew that the person confessing to a crime was not the person who did it and they'd be letting the guilty person go free, could they choose not to accept this person's confession and proceed with charging the original person? Has there been any cases where this happened?