State v. Walker, 433 P.3d 202

Defendant Randall Walker was convicted by a jury of two counts of incest and two counts of sexual assault based on longstanding abuse of one step‑daughter (A.W.) and an alleged incident with a second step‑daughter (R.W.) on Feb. 14, 2015.
Walker sought to introduce three categories of defense evidence at trial: (1) results of a voluntarily‑taken polygraph (examiner Dick Stotts); (2) a psychosexual evaluation by Dr. Robert Page concluding Walker had no sexual interest in children; and (3) testimony from Stacy Wood about an alleged prior sexual incident involving R.W. and a three‑year‑old.
The State moved pretrial to exclude the polygraph and Dr. Page’s testimony and to bar Wood’s proposed testimony under Montana’s Rape Shield statute. The district court granted the State’s motions.
Walker was convicted on all counts and appealed, raising three evidentiary challenges: exclusion of polygraph evidence, exclusion of psychosexual‑profile testimony, and exclusion of evidence of the alleged prior sexual conduct of the victim (R.W.).
The Montana Supreme Court affirmed: it reiterated Montana’s long‑standing ban on polygraph evidence, held psychosexual profile/test‑result evidence inadmissible when it purports to show the defendant does not fit a sexual‑offender profile, and found the Rape Shield exclusion properly applied after balancing the interests.

Issue	Walker's Argument	State's Argument	Held
Admissibility of polygraph results	Polygraph results (and expert testimony under M. R. Evid. 702) assist factfinder and show Walker’s consciousness of innocence/truthfulness	Montana precedent bars polygraph evidence as unreliable and invading jury’s province	Affirmed exclusion; Montana prohibits polygraph evidence in court proceedings because it improperly comments on credibility and invades the jury’s role
Admissibility of psychosexual evaluation (Dr. Page)	Dr. Page’s clinical findings (no sexual interest in children) are expert opinion under Rule 702 relevant to intent/knowledge, not mere credibility bolstering	Test results would impermissibly bolster defendant, speak to guilt/innocence, and invade jury province	Affirmed exclusion; profile/test‑result evidence that defendant does not fit a pedophile profile impermissibly bolsters innocence and invades jury role
Admission of prior sexual conduct evidence re: R.W. (Wood)	Prior incident shows R.W.’s sexual knowledge/awareness and bears on her credibility/conflicting testimony on the day of the alleged assault	§ 45‑5‑511(2) MCA (Rape Shield) bars evidence of victim’s sexual conduct; proffered evidence is speculative/hearsay and not sufficiently probative	Affirmed exclusion; court balanced constitutional confrontation/presentation rights against Rape Shield, found proffer speculative/unsupported and exclusion proper

State v. Bashor, 188 Mont. 397 (Mont. 1980) (polygraph testimony invades jury province and improperly comments on credibility)
State v. Staat, 248 Mont. 291 (Mont. 1991) (Montana rule: polygraph evidence not allowed in court proceedings)
United States v. Alexander, 526 F.2d 161 (8th Cir. 1975) (polygraph creates an "aura of infallibility" and undermines jury factfinding)
United States v. Scheffer, 523 U.S. 303 (1998) (courts note juror reliance risk from lie‑detection evidence)
State v. Spencer, 339 Mont. 227 (Mont. 2007) (excluding psychosexual‑profile testimony that a defendant lacked diagnostic criteria of a pedophile)
State v. Bailey, 320 Mont. 501 (Mont. 2004) (psychosexual evaluation excluded when it would bolster defendant’s credibility)
State v. Passmore, 355 Mont. 187 (Mont. 2010) (no per se rule for profile evidence; admissibility requires careful application of Rules 403, 404, 405, and 702)