MEMORANDUM **

Kenneth Helgeson appeals from the 57-month sentence imposed following a jury-trial conviction for involuntary manslaughter, in violation of 18 U.S.C. §§ 1153 and 1112(a). We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.

Helgeson contends that the district court erred by denying his motion for acquittal pursuant to Federal Rule of Criminal Procedure 29 because the evidence was insufficient to sustain a conviction. Taking the evidence in the light most favorable to the government, a reasonable jury could have found beyond a reasonable doubt that Helgeson was guilty of involuntary manslaughter. See United States v. Lopez-Martinez, 543 F.3d 509, 515 (9th Cir. 2008).

Next, Helgeson contends that the district court procedurally erred by failing to adequately explain the sentence imposed. The district court did not procedurally err. See United States v. Carty, 520 F.3d 984, 992 (9th Cir. 2008) (en banc).

Finally, we decline to address Helgeson’s contention that his sentence is substantively unreasonable, as he failed to raise this contention in his opening brief. See United States v. Montoya, 45 F.3d 1286, 1300 (9th Cir. 1995).

AFFIRMED.