During trial, the defense counsel make many decisions; sometimes there is an objection to evidence, sometimes not. How the appellate courts deal with allegedly inadmissible evidence depends on whether there was an objection at trial.
If there is an objection the appellate court looks to see if the evidence was objectionable, whether the judge abused his discretion in overruling the objection, and if the error was harmful or harmless (prejudice).
If there is no objection the appellate court may apply the plain error rule.
Where an appellant has not challenged the admission of evidence at trial, the standard of review is plain error. United States v. Powell, 49 M.J. 460 (C.A.A.F. 1998). To prevail under a plain error analysis, Appellant must demonstrate that (1) there was error, (2) the error was clear or obvious, and (3) the error materially prejudiced a substantial right. United States v. Lopez, 76 M.J. 151, 154 (C.A.A.F. 2017) (citation omitted).
So we get to United States v. Langhorne, from the Air Force Court of Criminal Appeals to use as an example.
Appellant raises one issue on appeal: Did the military judge abuse his discretion when he failed to require trial counsel to establish a good faith basis for asking a defense character witness if she was aware “Appellant had previously lied under oath?” We find that Appellant, not having raised the issue at trial, has failed to demonstrate plain error that materially prejudiced his substantial rights. Accordingly, we affirm the findings and sentence.
Alert, there is another issue in the case that wasn’t addressed–a witness impeaching the verdict. Apparently, a sentencing witness said: “that she did not believe Appellant had committed the offenses to which he pleaded guilty.” Slip op. at 4. Make every effort to make sure sentencing witnesses do not impeach the verdict when testifying!