¶40 The test for this harmless error was set forth by the Supreme Court in Chapman v. California, 386 U.S. 18 (1967), reh’g denied, 386 U.S. 987 (1967). There, the Court explained that, “before a federal constitutional error can be held harmless, the court must be able to declare a belief that it was harmless beyond a reasonable doubt.” Id. at 24. An error is harmless if the beneficiary of the error proves “beyond a reasonable doubt that the error complained of did not contribute to the verdict obtained.” Id.  Here, the State must carry the burden of proof.¶41 As noted in Hale, __ Wis. 2d__, ¶61, this court has articulated several factors to aid in its harmless error analysis. These include the frequency of the error, the importance of the erroneously admitted evidence, the presence or absence of evidence corroborating or contradicting the erroneously admitted evidence, whether the erroneously admitted evidence duplicates untainted evidence, the nature of the defense, the nature of the State’s case, and the overall strength of the State’s case. Id. (citing State v. Norman, 2003 WI 72, ¶48, 262 Wis. 2d 506, 664 N.W.2d 97; State v. Billings, 110 Wis. 2d 661, 668-70, 329 N.W.2d 192 (1983)).
Every other Justice has something to say on the articulation of the correct test for harmless error. If you’re sufficiently interested to try cobbling together 4 votes in favor of some coherent whole, you could probably add the 3-vote dissent to Justice Prosser’s concurrence – taken together, they seem to locate the test in State v. Harvey, 2002 WI 93.