Can Scott Panetti be executed for the murder of his wife's parents, Joe and Amanda Alvarado? We don't know. What is the standard for determining mental competence for execution? We don't know. Can a condemned murderer omit any claim of incompetence in his first federal habeas petition and then claim incompetence in a new petition without meeting the stringent requirements set by Congress for "second or successive petitions"? Yes, but he probably has to ask the state court first, and Congress's limits on relitigation will apply if the state court doesn't blow it.
That's pretty much what today's decision in Panetti v. Quarterman says. Procedural issues are resolved largely as expected, but the substantive Eighth Amendment question is not resolved. Justice Thomas in dissent calls this decision "half-baked."
The bright side of today's opinion is that Justice Kennedy makes clear we are talking about psychotic disorders, not the broad sweep of "mental illness" as including every collection of behaviors that has a code in the APA's Diagnostic and Statistical Manual (DSM). Here is the best part:
Someone who is condemned to death for an atrocious murder may be so callous as to be unrepentant; so self-centered and devoid of compassion as to lack all sense of guilt; so adept in transferring blame to others as to be considered, at least in the colloquial sense, to be out of touch with reality. Those states of mind, even if extreme compared to the criminal population at large, are not what petitioner contends lie at the threshold of a competence inquiry. The beginning of doubt about competence in a case like petitioner’s is not a misanthropic personality or an amoral character. It is a psychotic disorder.