State v. W. Cunningham, 414 P.3d 289

On Aug. 1–2, 2014, William Cunningham (63, Army veteran) and Nathan Horn (40, Marine veteran) drank and argued outside an apartment complex; the argument escalated over two evenings.
During an August 2 altercation Cunningham used a knife to cut Horn’s throat; Horn bled profusely and died during transport. Cunningham was arrested; his BAC was 0.217 within two hours.
The State charged Cunningham with deliberate homicide with a weapons enhancement; Cunningham asserted a justifiable-use-of-force (self‑defense) affirmative defense, claiming Horn threatened and advanced on him.
At trial the court excluded several out‑of‑court statements Horn allegedly made to Cunningham (e.g., that he was a sniper, had hand‑to‑hand training, threatened to "kick [him]"), and precluded defense impeachment of the State’s medical examiner based on a letter alleging prior misconduct and false testimony.
The jury convicted Cunningham and the district court sentenced him to 80 years; on appeal Cunningham argued these evidentiary rulings (and the court’s handling of juror media concerns) produced cumulative error requiring a new trial.

Issue	State's Argument	Cunningham's Argument	Held
Exclusion of Horn’s out‑of‑court statements	Statements were hearsay, irrelevant or impermissible character evidence of victim	Statements were non‑hearsay when offered to show Cunningham’s and Horn’s state of mind and explain reasonableness of force	Reversed: exclusion was erroneous; statements were admissible to show state of mind
Preclusion of impeachment of Dr. Bennett using letter alleging misconduct	Letter contained hearsay allegations, was more prejudicial than probative, risked collateral "mini‑trial"	Letter allegations were highly probative of Dr. Bennett’s credibility and competence; limited inquiry should be allowed	Reversed: court abused discretion by forbidding even limited impeachment inquiry
Handling of juror media/photograph concerns	No evidence of prejudice; public trial norms; court acted within discretion	Defense asked polling to detect intimidation/bias and sought mistrial	Affirmed in part: court within discretion to decline full polling though better practice would be to inquire; not reversible here
Cumulative‑error doctrine	Errors were harmless or minimal and did not deprive defendant of fair trial	Combined evidentiary errors prejudiced ability to present self‑defense and impeach key expert	Reversed: cumulative effect of erroneous exclusions denied fair trial; remanded for new trial

State v. Hardman, 276 P.3d 839 (Mont. 2012) (abuse‑of‑discretion standard for evidentiary rulings)
State v. Kirkland, 602 P.2d 586 (Mont. 1979) (trial court discretion on interrogating jury about media exposure)
State v. Branham, 269 P.3d 891 (Mont. 2012) (only facts known to defendant at incident relevant to self‑defense)
State v. Weinberger, 665 P.2d 202 (Mont. 1983) (state of mind and parties’ relations relevant in self‑defense inquiry)
State v. Hauer, 279 P.3d 149 (Mont. 2012) (limits on victim character evidence when accused asserts self‑defense)
State v. Eagan, 582 P.2d 1195 (Mont. 1978) (presumption of prejudice for proven jury misconduct unless interrogation disproves prejudice)
State v. Weisbarth, 378 P.3d 1195 (Mont. 2016) (prior false testimony is favorable impeachment evidence)
Kills on Top v. State, 928 P.2d 182 (Mont. 1996) (cumulative‑error doctrine can warrant reversal)
State v. Lawrence, 385 P.3d 968 (Mont. 2016) (cumulative errors rarely merit reversal but may when prejudice shown)