Unfortunately, it appears you have exhausted your appeal rights in this situation. I would however tell you to contact the State Appellate Defender's Office (http://www.sado.org) to inquire with them specifically about the possibility of a 6500 Motion.
Based on what you have written, I would be a bit skeptical about your realistic possibilities of filing an additional appeal / 6500 Motion, however I rarely deal with appeals, while the attorneys at SADO solely represent individuals on appeal.
Best of Luck.
An Attorney-Client relationship has not been established. Becket J. Jones is not your attorney. In order to protect your interests, you should engage with and retain a competent criminal defense attorney who practices often in the court you are scheduled to be in front of if you have been (or believe you will be) charged with a crime in the State of Michigan.
I am sorry to hear about your situation. I agree with the attorney that recommended contacting SADO.
This answer is legal information only. It does not create an attorney-client relationship between you and the Law Office of John Freeman, PLLC. General answers to questions on this site are not intended as a substitute for personal consultation with a qualified attorney.
Your question, unfortunately, leaves out important information that a lawyer would need to know in order to give you specific advice. The lawyers who answered your question are referring, correctly, to a rule that allows a convicted person one last chance to get justice, even if they have already lost their appeal as of right to the Court of Appeals and their appeal by permission to the Supreme Court. The law dealing with this one last chance can be found in MCR 6.500 - 6.509. You will have to show the judge who tried your case (or his successor) a reason (one that was not previously raised on appeal) why you did not get a fair trial. You need to show either that this error would likely have made the difference between winning and losing, or you have to show that you are actually innocent. You also have to give an explanation of why this error was not raised in your appeal as of right. (Ineffective assistance of trial or appellate counsel may be a possible reason.) The judge's decision is appealable (by permission to the Court of Appeals and Supreme Court. What concerns me is that you mention that the trial was 30 years ago, and you imply that you went back to court fairly recently (although you do not say when). If you have already used the 6.500 procedure I've discussed in this answer, you cannot do so again. As far as the recommendation that you contact the State Appellate Defender is concerned, it is very unlikely that it would be able to jump in under these circumstances. It generally handles assignments of appeals from the courts (it gets about 1/3 of all appointed appeals, so they're already very busy) under guidelines established by the State Appellate Defender Commission. If, however, you are able to file a basic 6.500 Motion on your own or through the assistance of counsel, showing merit to your argument, you can request the appointment of either a certified appellate attorney through the Michigan Appellate Assigned Counsel System or the State Appellate Defender's Office.
(This response should not be considered specific legal advice as to specific legal problems. It is a general overview intended to provide the questioner with general legal principles which he or she might find helpful in further researching his or her situation and in determining whether to consult with an attorney about the specific facts of the matter. The law is generally more complex than the brief overwview provided here. The questioner should not act in reliance upon this response; rather, any legal decisions made should be based on an individual consultation with a qualified attorney.)