State v. Buckles, 420 P.3d 511

Trooper stopped Morris Buckles for speeding; officer smelled marijuana, recovered a glass jar of marijuana, a meth pipe, and $740 on Buckles; vehicle later impounded and searched revealing a second meth pipe and $20,400 in cash packaged with rubber bands, GPS and two cell phones.
State charged Buckles with felony use/possession of property subject to criminal forfeiture (money intended for drug distribution), felony criminal possession of dangerous drugs, and two misdemeanors relating to drugs and paraphernalia.
Nine months after the Montana stop, Buckles was arrested and charged in Utah with methamphetamine distribution-related offenses; State sought to admit those Utah charges as rebuttal evidence to prove intent to use the Montana cash for drug transactions.
District Court allowed limited rebuttal testimony from a Drug Task Force agent about the Utah charges and gave limiting instructions to the jury; the Utah charges were not introduced in the State’s case-in-chief.
Jury convicted on all counts; Buckles appealed arguing admission of the Utah charges was improper under M. R. Evid. 404(b) and 403 because it improperly suggested propensity and was unfairly prejudicial.
Supreme Court majority held the District Court abused its discretion under Rule 403: probative value did not outweigh risk of unfair prejudice, the error was not harmless, and remanded for a new trial; one justice dissented.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admissibility of Utah drug charges as Rule 404(b) evidence to prove intent	Utah charges relevant to Buckles's intent to use cash for drug distribution; admissible on rebuttal	Admission unfairly suggested propensity/character and was unduly prejudicial under Rule 403	Court: Although relevant under 404(b), admission violated Rule 403 because unfair prejudice substantially outweighed probative value; evidence improperly admitted
Whether limiting instruction cured prejudice	State: limiting instruction and restricting testimony to rebuttal mitigated prejudice	Buckles: jury likely penalized him for unproven bad acts despite instruction	Held: limiting instruction insufficient; prejudice remained substantial
Harmless-error analysis for admission of tainted evidence	State: error was harmless because other evidence supported intent	Buckles: tainted evidence could have contributed to conviction; not harmless	Held: admission was trial error and not harmless; reasonable probability the evidence contributed to conviction
Proper use of subsequent (post‑incident) acts to prove intent	State: subsequent acts can be probative of state of mind and used to rebut defense explanations	Buckles: subsequent acts treated like prior bad acts and unfairly prejudicial	Held: subsequent acts, though potentially relevant, were excluded here due to Rule 403 prejudice outweighing probative value

State v. Blaz, 388 Mont. 105, 398 P.3d 247 (2017) (district courts have broad discretion on evidentiary rulings; limiting instructions may cure prejudice)
State v. Stewart, 367 Mont. 503, 291 P.3d 1187 (2012) (404(b) evidence still subject to 403 balancing; unfair prejudice occurs when evidence prompts improper jury decision)
State v. Madplume, 386 Mont. 368, 390 P.3d 142 (2017) (definition of unfair prejudice under Rule 403)
State v. Lamarr, 376 Mont. 232, 332 P.3d 258 (2014) (most prosecution evidence is prejudicial; 403 excludes only when prejudice substantially outweighs probative value)
State v. Van Kirk, 306 Mont. 215, 32 P.3d 735 (2001) (two-step harmless-error analysis distinguishing structural and trial error)
State v. Derbyshire, 349 Mont. 114, 201 P.3d 811 (2009) (when tainted evidence was admitted to prove an element, state must point to admissible evidence proving same facts)
State v. Hegg, 288 Mont. 254, 956 P.2d 754 (1998) (cash alone can have lawful purposes; convictions cannot rest on mere suspicion that cash is traceable to drug sales)