The police didn't read me my rights! Don't they have to dismiss my case?

The police are not required to read everyone they arrest Miranda warnings. Police only have to advise you of your right to remain silent if you are (1) in custody, and (2) are subjected to custodial interrogation by law enforcement. Even if you are in custody and interrogated by the police without being warned of your Miranda rights, the court will only prohibit the prosecutor from using at trial any statements you made as a result of the illegal interrogation. It will not automatically result in a dismissal of your charges.