Former Detroit police officer Burt Lancaster shot and killed his girlfriend, Toni King, in 1993. As a result, the State of Michigan charged Burt Lancaster with first-degree murder and possession of a firearm while committing a felony. Although Lancaster, who has a history of mental illness, asserted both defenses of insanity and diminished capacity during his initial trial in 1994, a Michigan jury convicted Lancaster on both counts. Lancaster's conviction was subsequently overturned, however, because of an error made by the State during jury selection. The State of Michigan retried Lancaster in 2005. Although Lancaster planned to rely completely on his diminished capacity defense during his second trial, the Michigan trial court prohibited Lancaster from doing so on the grounds that the Michigan Supreme Court abolished the defense in 2001. As Lancaster was unable to assert the diminished capacity defense at his second trial, the Michigan state court convicted Lancaster once again and sentenced him to life plus two years in prison. Lancaster petitioned the federal courts for a writ of habeas corpus. While the District Court denied Lancaster's petition, the Sixth Circuit reversed, finding that the retroactive application of the Michigan Supreme Court's abolishment of the diminished capacity defense violated federal due process. On appeal, the State of Michigan argues that the Michigan state court's decision to prohibit the diminished capacity defense was not an "unexpected and indefensible" abrogation of Michigan law because the diminished capacity defense has never been expressly provided by Michigan statute nor has it been a part of settled Michigan common law. Lancaster responds that he has the constitutional right to present the diminished capacity defense because the defense was well-settled under Michigan law and available to him at the time he committed the murder. The State of Indiana and others argue in support of Michigan, asserting that diminished capacity is a state law issue and federal courts should defer to a state court's analysis. Lancaster responds that the Michigan state court's decision was unreasonable and that a federal court should independently review the Michigan state court's determination. This decision will further outline the prohibition on changes in state judge-made law by determining when the retroactivity prohibition can be used to justify granting habeas corpus relief and by further defining what constitutes an "unexpected and indefensible" change to the common law.