Miss. Code Ann. § 99-39-21: Procedural waiver of objections, defenses, claims; collateral estoppel; res judicata; burden of proof.

(1) Failure by a prisoner to raise objections, defenses, claims, questions, issues or errors either in fact or law which were capable of determination at trial and/or on direct appeal, regardless of whether such are based on the laws and the Constitution of the state of Mississippi or of the United States, shall constitute a waiver thereof and shall be procedurally barred, but the court may upon a showing of cause and actual prejudice grant relief from the waiver.

(2) The litigation of a factual issue at trial and on direct appeal of a specific state or federal legal theory or theories shall constitute a waiver of all other state or federal legal theories which could have been raised under said factual issue; and any relief sought under this article upon said facts but upon different state or federal legal theories shall be procedurally barred absent a showing of cause and actual prejudice.

(3) The doctrine of res judicata shall apply to all issues, both factual and legal, decided at trial and on direct appeal.

(4) The term “cause” as used in this section shall be defined and limited to those cases where the legal foundation upon which the claim for relief is based could not have been discovered with reasonable diligence at the time of trial or direct appeal.

(5) The term “actual prejudice” as used in this section shall be defined and limited to those errors which would have actually adversely affected the ultimate outcome of the conviction or sentence.

(6) The burden is upon the prisoner to allege in his motion such facts as are necessary to demonstrate that his claims are not procedurally barred under this section.