Appeals court hears challenge to expert testimony in State v. Walker; prosecutor says error was harmless

An appellate panel heard oral arguments in State of Washington v. Jake Walker on whether trial testimony by a medical expert improperly invaded the jury's role and, if so, whether the error was harmless.

Oliver Davis, defense counsel for Walker, told the court that Dr. Susan Reed’s trial testimony went beyond permissible expert opinion and crossed into statements about intent. Davis recounted that Dr. Reed told jurors that "most sexual assaults don't involve this injury" and later described the injury as not accidental, arguing those comments violated a pretrial limine ruling and "could not be unrung" despite the trial court’s instruction to disregard the remark.

"The injuries were not caused intentionally. They were at worst negligent," Davis said in argument, framing the appeal around whether the jury was improperly influenced by the doctor's statements.

Andrea Vitalich of the King County Prosecutor’s Office told the court the convictions should be affirmed. Vitalich conceded a constitutional error occurred when an expert opines on guilt or intent but urged the panel to apply the higher harmless-error test the state said the court clarified in Magania Arevalo. She described the error as isolated and said the remaining evidence — including the victim's testimony, photos, body-worn video, SANE nurse and police testimony — provided "overwhelming" untainted support for the jury's findings.

Vitalich argued that jurors saw evidence such as bruising consistent with strangulation and a substantial head injury that, when combined with video of the defendant's behavior and other testimony, made an accidental explanation implausible. She also disputed that the doctor's statement that the injury pattern is unusual in sexual assaults improperly expressed an opinion about guilt, calling it an expert's observation about injury patterns.

Panel members questioned both sides on whether the doctor's remark was truly isolated and on related procedural doctrines. One judge asked whether a juror's request for Walker's toxicology report and other deliberative questions indicated that the case was close; Davis said those jury inquiries supported his argument that the error was prejudicial. Another panel member queried whether pointing out what the defendant did not say could implicate Salinas or other Miranda-related lines of cases; the prosecutor replied that the relevant video showed Mr. Walker shouting and interacting with officers in a noncustodial setting, so silence-based concerns were not present.

Davis pressed the court to reverse and remand, citing the jury's questions, a previous hung jury in an earlier trial, and Carlson-related precedent as showing the verdict rested on a close factual record. After rebuttal argument, the matter was submitted for decision.

The appeals panel did not issue a decision at the hearing; no procedural ruling was entered on the record following argument. The court moved on to the next scheduled matter.