Osborne v. State, 285 P.3d 248

Osborne charged with Wyoming first-degree murder; defense pursued voluntary intoxication defense asserting lack of specific intent.
Trial evidence showed heavy drinking and Adderall use; witnesses testified Osborne was intoxicated the night of the killing.
Osborne testified he drank heavily but claimed not to recall precise events; defense argued intoxication prevented premeditation.
Jury was instructed that self-induced intoxication could negate premeditation; jury nonetheless found Osborne guilty of first-degree murder.
Post-verdict, new counsel presented Dr. Beaver's testimony claiming substance abuse delirium; district court denied new trial; conviction upheld on appeal.
Standards: ineffective-assistance claim requires deficient performance and prejudice; review is de novo.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Was trial counsel ineffective for not securing expert testimony on substance abuse delirium?	Osborne asserts deficient performance prejudiced defense.	State contends counsel reasonably investigated and presented the intoxication defense without error.	No prejudice; conviction affirmed.

Strickland v. Washington, 466 U.S. 668 (U.S. 1984) (establishes deficient performance and prejudice standard)
Ken v. State, 267 P.3d 567 (Wyoming 2011) (de novo review for ineffective-assistance claims)
Sanchez v. State, 253 P.3d 136 (Wyoming 2011) (deficient performance and prejudice framework applied)
Lopez v. State, 86 P.3d 851 (Wyoming 2004) (duty to investigate or reasonably decide investigations for experts)
McCoy v. State, 886 P.2d 252 (Wyoming 1994) (reasonableness of investigative decisions for defense)
Sincock v. State, 76 P.3d 323 (Wyoming 2003) (prejudice inquiry under Strickland in context of overwhelming evidence)
Harlow v. State, 105 P.3d 1049 (Wyoming 2005) (necessity of proving prejudice in ineffective assistance cases)
Montez v. State, 201 P.3d 434 (Wyoming 2009) (exceptional prejudice showing framework in Strickland claims)