[T]he Court's holding . . . places no new restriction on the States' freedom
to determine whether, and to what extent, mental illness should excuse
criminal behavior. The Court does not indicate that States must make the
insanity defense available. See Idaho Code § 18-207(a) (1987) (mental
condition not a defense to criminal charges); Mont. Code Ann. § 46-14-
102 (1991) (evidence of mental illness admissible to prove absence of
state of mind that is an element of the offense).
Foucha, 504 U.S. at 88-89 (O'Connor, J., concurring).2 In a separate opinion, Justice
Kennedy also notes:
Consistent with the general rule that the definition of both crimes and
defenses is a matter of state law, see Patterson v. New York, 432 U.S.[,
197,] 210[, 97 S. Ct. 2319, 53 L. Ed. 2d 281 (1977)], the States are free to
recognize and define the insanity defense as they see fit.
Foucha, 504 U.S. at 96 (Kennedy, J., dissenting).
In determining retroactivity, our supreme court attempts to maintain congruence
with the United States Supreme Court decision in Teague. In re Pers. Restraint of
Markel, 154 Wn.2d 262, 268, 111 P.3d 249 (2005). In Teague, the Court held that in
general, "new constitutional rules of criminal procedure will not be applicable to those
cases which have become final before the new rules are announced." Teague, 489
U.S. at 310.