Harmless Error and Showing Prejudice

Establishing that a court made a mistake is only half of an appeal. The other half is establishing that the mistake mattered. Congress made this explicit in 28 U.S.C. 2111, which directs the courts of appeals to give judgment after examination of the record without regard to errors or defects that do not affect the substantial rights of the parties.

The rule, and where it appears

The same instruction appears in three other places. Federal Rule of Civil Procedure 61 says that at every stage of the proceeding the court must disregard all errors and defects that do not affect any party's substantial rights, and that no error in admitting or excluding evidence is ground for a new trial unless justice requires otherwise. Federal Rule of Criminal Procedure 52(a) states that any error that does not affect substantial rights must be disregarded. Federal Rule of Evidence 103(a) conditions a claim of evidentiary error on the ruling affecting a substantial right.

The repetition reflects how central the idea is. Trials are long, the rules are numerous, and a proceeding conducted without any error at all is rare. If every deviation produced a new trial, few judgments would ever become final. The doctrine accepts imperfection and asks only whether the imperfection changed anything.

Prejudice in civil litigation

In a civil case the party seeking reversal ordinarily bears the burden of showing prejudice. Formulations differ across circuits: some ask whether the error more probably than not affected the outcome, others whether the reviewing court can say with fair assurance that the judgment was not substantially swayed. Both ask the same practical question about the weight of the error against the rest of the record.

Evidentiary errors are the usual setting. An erroneously admitted document that duplicates admitted testimony is harmless. An erroneously excluded document that was the only proof of a contested element is not. Instructional errors are assessed by reading the charge as a whole, since a misstatement in one sentence may be corrected by the surrounding instructions.

Nonconstitutional and constitutional error

Criminal appeals divide the inquiry. For preserved nonconstitutional error, courts generally ask whether the error had a substantial and injurious effect or influence in determining the verdict, or whether the court can say with fair assurance that the judgment was not substantially swayed. The government usually carries the burden on a preserved claim, though the phrasing varies.

For preserved constitutional error the standard is stricter. The government must show that the error was harmless beyond a reasonable doubt, meaning there is no reasonable possibility that it contributed to the verdict. The reviewing court asks about the effect on this jury's verdict rather than whether the remaining evidence would have supported a conviction.

Errors that are not measured at all

A small category of errors is exempt from the inquiry. Structural errors affect the framework within which the trial proceeds rather than a discrete step within it, so their consequences cannot be assessed by comparing them with the rest of the record. Recognized examples include the complete denial of counsel, a judge who is not impartial, unlawful exclusion of members of the defendant's race from a grand jury, denial of self-representation, and denial of a public trial.

Because the category produces automatic reversal, courts have kept it small and have resisted arguments to extend it. Most trial defects, including serious ones, are treated as trial errors that occurred during the presentation of the case and can therefore be weighed against everything else that happened.

Building the prejudice argument

Prejudice is shown from the record, not asserted. The strongest arguments identify what the excluded evidence would have established, quote the closing argument that relied on the improper material, point to a jury question that shows the issue was contested, or show that the verdict turned on a single element the error touched. Vague assertions that a jury may have been influenced are treated as no argument at all.

This is where the composition of the record becomes decisive, and why the choices described in assembling the record and ordering the transcript should be made with the prejudice argument in mind. An appellant who orders only part of a transcript often cannot show what the rest contained, and the court will assume it supported the judgment.

Where preservation changes the calculation

The same error can be reviewed under two different frameworks depending on what happened at trial. Preserved, it is measured under the standards above with the burden usually on the party defending the judgment. Forfeited, it goes into the four-part plain error test and its allocation to the appellant, where the burden is reversed and correction remains discretionary.

That difference is the practical reason for the discipline described in the objection, offer of proof and instruction requirements. It is also why an appellee's brief usually argues, in order, that there was no error, that any error was harmless, and that the claim was not preserved in any event. Each argument survives the failure of the others.