What is the test for a finding that the evidence at trial was insufficient to support a conviction?

When reviewing a challenge that the evidence at trial was insufficient to support a conviction, we must determine whether any rational trier-of-fact could have found the essential elements of the crime to have been proven beyond a reasonable doubt. United States v. Adler, 879 F.2d 491, 495 (9th Cir.1988). In making that determination, the evidence must be viewed in the light most favorable to the government. United States v. Mundi, 892 F.2d 817, 820-21 (9th Cir.1989), cert. denied, 498 U.S. 1119, 111 S.Ct. 1072, 112 L.Ed.2d 1178 (1991).