When defendants appeal their convictions they present all the errors they think the trial judge made (and some they’re just hoping the appellate court will buy). Defendants typically offer several arguments about the inadequacy of the trial that led to the conviction. For example, they may argue that jury instructions were erroneous or that the prosecution misbehaved. But, believe it or not, courts often acknowledge that errors occurred, yet refuse to do anything about them.
Appellate court judges sometimes remark that defendants are entitled to trials that are fair, not perfect. Their thinking is that defendants are entitled to nothing more than a just determination of the truth, and that “harmless” errors do nothing to compromise that determination.
Normal Errors. The ordinary test for harmless error is whether the mistake in question affected the “substantial rights” of the defendant. If the alleged error didn’t involve a constitutional right, the government must generally show a “fair assurance” that the error didn’t significantly affect the verdict. For example, suppose a judge erroneously admitted a police officer’s hearsay and that hearsay described the defendant’s confession. Without the hearsay, the confession would have been inadmissible, and there wasn’t any other evidence directly tying the defendant to the crime. In that situation, the error is harmful—even if the appellate court were to judge it under the higher standard for errors that violate constitutional rights (described below). The appellate court will reverse the conviction. (United States v. Duenas, 691 F.3d 1070 (9th Cir. 2012).)
Constitutional Errors. Certain errors require that the prosecution unequivocally establish “harmlessness.” If an error involves a constitutional right—for example, visibly and unjustifiably shackling the defendant during trial in violation of due process—the prosecution must prove beyond a reasonable doubt that the error didn’t contribute to the guilty verdict. (People v. Hernandez, 51 Cal. 4th 733 (2011).)
Structural Errors. There are some errors, though exceedingly rare, that automatically require appellate courts to reverse convictions. These include:
(State v. Abram, 284 Neb. 55 (2012).)
It’s unusual for appellate courts to disturb not only convictions, but also sentences. Trial judges often have considerable discretion in sentencing, discretion that appellate courts respect. However, appeals courts may modify (or order trial courts to modify) sentences in various instances, including when those sentences:
(For more on this area, see Appealing a Sentence.)
If you’ve been convicted of a crime and are considering appealing the conviction or sentence, consult an experienced criminal defense attorney. Appellate criminal defense lawyers specialize in post-trial proceedings and will be able to tell you more about the kinds of errors that can cause a court to reverse a conviction or alter a sentence.