Guillen v. State, 415 P.3d 1

July 30, 2011: Alberto Guillen drove a van into his brother Roberto during an altercation; Roberto was severely injured and partially paralyzed.
State charged Guillen with attempted deliberate homicide and leaving the scene; charge reduced to attempted mitigated homicide; Guillen signed a written guilty plea and entered an open plea on November 10, 2011.
December 29, 2011: Court sentenced Guillen to 40 years for attempted mitigated homicide and 10 years concurrent for leaving the scene.
Guillen later moved to withdraw his plea alleging counsel promised a 15-year sentence; motion denied and denial affirmed on direct appeal.
In a 2015 postconviction petition Guillen asserted newly discovered evidence (Roberto later testified the collision might have been an accident) and ineffective assistance of counsel for failing to interview Roberto.
District Court held an evidentiary hearing, found eyewitnesses credible, found Roberto not credible, concluded counsel’s decision not to interview Roberto was tactical, and denied relief; Supreme Court affirmed.

Issue	Guillen's Argument	State's Argument	Held
Whether Roberto’s new testimony establishes actual innocence so as to permit postconviction relief	Roberto’s later statement that he may have swerved shows the collision was accidental, negating mens rea for attempted mitigated homicide	The new testimony at best reduces culpability; eyewitnesses still support intentional act and Roberto’s testimony was not credible	Denied — new evidence did not establish actual innocence and court properly credited eyewitnesses over Roberto
Whether plea was involuntary due to ineffective assistance of counsel (failure to interview Roberto)	Counsel’s failure to interview Roberto left Guillen with incomplete facts and led to an involuntary plea	Counsel made a tactical decision not to interview Roberto to avoid exposing potentially harmful testimony; abundant evidence supported conviction risk	Denied — counsel’s choice was tactical (not deficient) and Guillen failed to show prejudice sufficient to undermine confidence in plea

Strickland v. Washington, 466 U.S. 668 (standard for ineffective assistance of counsel)
Marble v. State, 380 Mont. 366, 355 P.3d 742 (standard of review for denial of postconviction relief)
Cobell v. State, 320 Mont. 122, 86 P.3d 20 (ineffective-assistance claims reviewed de novo; Strickland application)
State v. Miner, 364 Mont. 1, 271 P.3d 56 (prejudice standard for plea withdrawal based on ineffective assistance)
Garrett v. State, 328 Mont. 165, 119 P.3d 55 (petitioner bears heavy burden in postconviction challenges)