Opinion ID: 1863488
Heading Depth: 2
Heading Rank: 2

Heading: Harmless Error Analysis of Evidentiary Decisions

Text: [6] ¶ 30. An erroneous exercise of discretion in admitting or excluding evidence does not necessarily lead to a new trial. The appellate court must conduct a harmless error analysis to determine whether the error affected the substantial rights of the party. If the error did not affect the substantial rights of the party, the error is considered harmless. [7] ¶ 31. Two statutes govern this situation, Wis. Stat. § 901.03 (Rulings on evidence) and Wis. Stat. § 805.18(2) (Mistakes and Omissions; Harmless Error). Section 901.03 provides that error may not be predicated on a ruling that admits or excludes evidence unless a substantial right of the party is affected. This statute must be read together with § 805.18(2), which provides that a new trial shall not be granted for an error unless the error has affected the substantial rights of the party. This latter provision, which dates back to the early years of Wisconsin statehood, [4] applies to both civil and criminal cases. [5] Martindale contends he deserves a new trial pursuant to this rule. [8, 9] ¶ 32. For an error to affect the substantial rights of a party, there must be a reasonable possibility that the error contributed to the outcome of the action or proceeding at issue. State v. Dyess, 124 Wis. 2d 525, 543, 547, 370 N.W.2d 222 (1985); see also Town of Geneva v. Tills, 129 Wis. 2d 167, 184-85, 384 N.W.2d 701 (1986) (noting that the standard set forth in Dyess applies in civil cases as well as criminal cases). A reasonable possibility of a different outcome is a possibility sufficient to undermine confidence in the outcome. Dyess, 124 Wis. 2d at 544-45 (quotation omitted). Where the erroneously admitted or excluded evidence affects constitutional rights or where the outcome of the action or proceeding is weakly supported by the record, a reviewing court's confidence in the outcome may be more easily undermined than where the erroneously admitted or excluded evidence was peripheral or the outcome was strongly supported by evidence untainted by error. Id. at 545.