A motion for a mistrial should be denied for "defects that do not affect the substantial rights of the defendant" when "the record is sufficient to establish the defendant's guilt." State v. Brady, 2000 MT 282, ¶ 14, 302 Mont. 174, ¶ 14, 13 P.3d 941, ¶ 14 (citing State v. Berosik, 1999 MT 238, ¶ 20, 296 Mont. 165, ¶ 20, 988 P.2d 775, ¶ 20). ¶ 13 Taking these factors into account, we conclude that the District Court did not abuse its discretion in denying Hofeldt's motions for a mistrial.

Rules 801(a) and 803(1), M.R.Evid. For instance, contemporaneous notes based on personal observations are admissible as recorded present sense impressions. State v. Berosik, 1999 MT 238, ¶ 37, 296 Mont. 165, ¶ 37, 988 P.2d 775, ¶ 37 (citing City of Helena v. Hoy (1991), 248 Mont. 128, 131, 809 P.2d 1255, 1257). In this case, Doyle's note was a written assertion describing an event or condition, namely Hope's angry mood and Doyle's feelings, made immediately after she perceived the event or condition.

However, we will not reverse a conviction based on evidentiary error unless the error affected the substantial rights of the defendant. State v. Berosik, 1999 MT 238, ¶ 20, 296 Mont. 165, ¶ 20, 988 P.2d 775, ¶ 20. See also, § 46-20-701(2), MCA, ("[a]ny error, defect, irregularity, or variance that does not affect substantial rights must be disregarded").

However, "a judgment of conviction will not be reversed unless the error prejudiced or tended to prejudice the substantive rights of the defendant." State v. Berosik, 1999 MT 238, ¶ 20, 296 Mont. 165, ¶ 20, 988 P.2d 775, ¶ 20. We find reversible error based on prejudice to the defendant only where there is a reasonable possibility that the inadmissible evidence might have contributed to the conviction.

A mistrial should be denied, however, for technical errors or defects that do not affect the substantial rights of the defendant and the record is sufficient to establish the defendant's guilt. State v. Berosik, 1999 MT 238, ¶ 20, 296 Mont. 165, ¶ 20, 988 P.2d 775, ¶ 20. "Any error, defect, irregularity, or variance that does not affect substantial rights must be disregarded." Section 46-20-701(2), MCA.

We held there that evidence of flight or concealment does not violate Rule 404(b) when admitted to prove consciousness of guilt. Moore, 254 Mont. at 245, 836 P.2d at 607; see also State v. Berosik, 1999 MT 238, ¶ 27, 296 Mont. 165, 988 P.2d 775 ("Rule 404(b), M. R. Evid., does not apply to evidence of consciousness of guilt."). In Moore, we reversed the district court for excluding as subsequent bad acts evidence that the defendant in a homicide case "cleaned blood from the camper, discarded bullets and carpet, covered and repaired bullet holes, [and] spilled battery acid . . . to cover or clean material" in the days following the murder.

A motion for mistrial should be denied for technical errors or defects that do not affect the substantial rights of the defendant. See State v. Berosik, 1999 MT 238, ¶ 20, 296 Mont. 165, 988 P.2d 775. In determining whether a prohibited statement contributed to a conviction, the strength of the evidence against the defendant—together with the prejudicial effect of the testimony and whether a cautionary jury instruction could cure any prejudice—must be considered. Partin, 287 Mont. at 18, 951 P.2d at 1005–06.

In determining harmless error, we have often relied on the "overwhelming evidence" rule. See State v. Berosik, 1999 MT 238, ¶ 21, ___ Mont. ___, ¶ 21, 988 P.2d 775, ¶ 21. This Court has noted that the federal harmless error rule and Montana's harmless error rule are essentially the same, and that in either case overwhelming evidence of a defendant's guilt can render harmless a district court's error.

Under its inherent authority, the Court has imposed an appropriate sanction on the City of Missoula for the spoliation of the video. Peschel's argument that supervisory liability may be imposed on Wickman, Muir and Willoughby for failing to preserve the video is a veiled attempt to prosecute an independent tort for spoliation — a tort unavailable to Peschel under Montana law. Oliver v. Stimpson Lumber Co., 1999 MT 238, ¶¶ 32-34, 297 Mont. 336, 993 P.2d 11 (1999). See also Dkt. # 72 at 27-28.