Generally, "[w]e review a district court's ruling on admissibility of evidence for abuse of discretion." State v. Baze, 2011 MT 52, ¶ 7, 359 Mont. 411, 414, 251 P.3d 122, 123-24. This includes rulings on chain of custody. See Baze, ¶ 20; see also State v. McCoy, 2012 MT 293, ¶¶ 11, 19, 367 Mont. 357, 291 P.3d 568 (holding that a district court did not abuse its discretion by finding a sufficient chain of custody for the admission of latent fingerprint evidence). However, in Haffey v. State, 2010 MT 97, ¶ 9, 356 Mont. 198, 233 P.3d 315, the Supreme Court stated:
This is our seminal decision regarding postconviction DNA testing under § 46-21-110, MCA. At issue on appeal are the District Court's determinations under § 46-21-110(5)(b), (c), (e), MCA, which involve, respectively, the chain of custody of the evidence to be tested, whether identity was or should have been an issue at trial, and whether the DNA testing would establish whether the petitioner was the perpetrator of the crime of which he was convicted. We conclude that these determinations are mixed questions of fact and law, subject to de novo review. See United States v. Fasono, 577 F.3d 572, 575 (5th Cir. 2009) (similar chain-of-custody and likelihood-of-innocence determinations under federal DNA testing statute, 18 U.S.C. § 3600(a)(4), (a)(8), subject to de novo review); Illinois v. Urioste, 316 Ill. App. 3d 307, 736 N.E.2d 706, 710, 249 Ill. Dec. 512 (Ill. App. 2000) (question of whether identity was an issue under similar statute subject to de novo review); see also United States v. Jordan, 594 F.3d 1265, 1269-70 (10th Cir. 2010) (Lucero, J., concurring) (explaining propriety of de novo review); but see e.g. Washington v. Riofta, 166 Wn.2d 358, 209 P.3d 467, 473 (Wash. 2009) (applying abuse of discretion standard of review).