So who shouldn't have rights? Miranda kidnapped and raped a teenage girl. He was generally not that
great of a guy. I wouldn't call his death a tragedy, ironic maybe.

I'd say everyone should have rights. That's what makes them rights instead of privileges. But I think we tend to think of rights as something we should have, but they shouldn't. Straight marriage is a right but gay marriage is a privilege, habeas corpus is for citizens only, etc. Rationally this doesn't make any sense, but on an emotional level, it's very appealing to claim exclusive rights.

Did Miranda kidnap and rape a teenage girl? According to that article, the only evidence that he did was his confession, and false confessions weren't at all unusual prior to Miranda warnings. Personally, I'm willing to presume he was guilty, but I sure don't want that standard applied to me when someone accuses me of a crime I didn't commit. That tension is what I mean by "the problem with rights."

After the Supreme Court ruled on Miranda V. Arizona he was retried without his confession as evidence
and still found guilty.

Wasn't his retrial a case of double jeopardy, which people are protected against in the Constitution? I can't remember from my ConLaw class in college.

I just assumed he wasn't retried because he died only ten years after the trial, but according to Wikipedia, the story is much more interesting:

He was sentenced to thirty years in the second trial, which wasn't double jeopardy because there was new evidence - he confessed to his wife. But he was released on parole after less than ten years. Then he was arrested again for possession of a gun, but the charges were dropped, so he only went back for one year on parole violation. Then he got out just in time to get killed.

So the justice system apparently worked reasonably well up until his parole hearing.