State v. T. Mercier, 479 P.3d 967

Background

Trevor Mercier and Sheena Devine had a prior relationship; on Oct. 5–6, 2016 Mercier confronted Devine, who was later found dead the next morning with blunt-force injuries and her cellphone submerged in a pot of greasy water.
Mercier was arrested and charged with Deliberate Homicide and Tampering with Physical Evidence (he pleaded guilty to a separate Criminal Mischief count).
Devine’s phone was sent to DHS Special Agent Brent Johnsrud in Colorado, who extracted data and prepared a forensic report including two time-stamped photos from ~12:00:20–21 a.m.
The State sought and the trial court permitted Johnsrud to testify via live two-way videoconference over Mercier’s objection as a foundational witness to the phone extraction; a Montana agent then testified about Johnsrud’s report and the photos.
The midnight photos were the only physical evidence directly linking Mercier to handling the phone; an eyewitness also testified seeing Mercier inside the house around midnight.
Mercier was convicted of Deliberate Homicide and Tampering with Physical Evidence; on appeal he argued the two-way video testimony violated his confrontation rights, the error’s harmlessness was contested, and he raised prosecutorial-misconduct/plain-error claims regarding closing argument.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether admitting foundational testimony via live two-way videoconference violated the Confrontation Clause	State: two-way video was practical and justified by judicial economy and the testimony was foundational (not substantive)	Mercier: live two-way testimony denied face-to-face confrontation; expense and convenience do not justify dispensing with in-person testimony	Court held Johnsrud’s two-way video testimony violated the confrontation right because the State failed to show necessity to further an important public policy; admission was error
Whether the Confrontation Clause error was harmless for (a) Deliberate Homicide and (b) Tampering with Physical Evidence	State: error harmless beyond a reasonable doubt because other evidence supported convictions (eyewitness placed Mercier in house at midnight)	Mercier: photos were essential evidence tying him to the phone and to tampering; without them prejudice remains	Court: Error was harmless as to Deliberate Homicide (eyewitness corroboration was cumulative), but not harmless as to Tampering — conviction reversed because the photos were the sole link to handling the phone
Whether prosecutor’s closing argument warranted reversal under plain-error review	State: rebuttal comment addressed defense summation and gravity of the crime; not a basis for reversal	Mercier: prosecutor attacked defense counsel and unfairly linked counsel’s remarks to Mercier’s guilt	Court: no plain error; closing remarks did not require reversal under the record as a whole

Key Cases Cited

Mattox v. United States, 156 U.S. 237 (establishes face-to-face confrontation purpose)
Maryland v. Craig, 497 U.S. 836 (two-prong test: necessity to further important public policy and reliability safeguards for remote testimony)
Coy v. Iowa, 487 U.S. 1012 (case-specific findings required to dispense with face-to-face right)
California v. Green, 399 U.S. 149 (cross-examination central to truth-seeking; discussion of confrontation history)
Crawford v. Washington, 541 U.S. 36 (limits admission of testimonial out-of-court statements absent confrontation)
Chapman v. California, 386 U.S. 18 (prosecution bears burden to show constitutional error harmless beyond a reasonable doubt)
Delaware v. Van Arsdall, 475 U.S. 673 (factors for harmless-error review of confrontation violations)
Arizona v. Fulminante, 499 U.S. 279 (distinction between structural and trial errors)
Ohio v. Roberts, 448 U.S. 56 (reliability framework discussed in relation to Crawford and Craig)
United States v. Gigante, 166 F.3d 75 (2d Cir. view on applicability of Craig to two-way video)
United States v. Carter, 907 F.3d 1199 (9th Cir. application of Craig to two-way video and necessity analysis)