Johnson v. Texas ( 1993 )
Penry v. State ( 1985 )
Penry v. State ( 1995 )
Penry v. Lynaugh ( 1989 )
Boyde v. California ( 1990 )
Penry v. Johnson ( 2001 )
McKoy v. North Carolina ( 1990 )
Atkins v. Virginia ( 2002 )