U.S. v. Armstrong, 53 M.J. 76

Core Criminal Law Subjects: Evidence: Expert / Scientific Testimony

1. expert testimony of a psychologist impermissibly vouching for the credibility of a victim of sexual abuse is a nonconstitutional evidentiary error to be tested for harmlessness

Core Criminal Law Subjects: Witnesses: Experts

1. expert testimony of a psychologist impermissibly vouching for the credibility of a victim of sexual abuse is a nonconstitutional evidentiary error to be tested for harmlessness

Trial Stages: Merits: Instructions › Generally

1. although curative instructions can render an evidentiary error harmless, where expert testimony of a psychologist impermissibly vouched for the credibility of a victim of sexual abuse there were grave doubts about whether the military judge’s instructions could eliminate prejudicial impact of expert’s impermissible testimony

Trial Stages: Appeals: Harmless / Prejudicial Error

1. expert testimony of a psychologist impermissibly vouching for the credibility of a victim of sexual abuse is a nonconstitutional evidentiary error to be tested for harmlessness to determine whether the error itself had a substantial influence on the findings; if there was a substantial influence, or if one is left in doubt, the conviction cannot stand
2. expert testimony of a psychologist impermissibly vouching for the credibility of a victim of sexual abuse was not harmless where: (1) the case pitted the credibility of a senior noncommissioned officer against the ambiguous, uncertain testimony of a 17-year old girl; (2) appellant’s wife and 15 year old daughter supported his defense; (3) appellant’s pretrial statement admitted only accidental contact and poor judgment; (4) there was no physical evidence; (5) the victim was not a strong witness and the expert was powerful; and (6) curative instructions did not remove grave doubts about whether the error was harmless