State of Iowa v. Michael Triplett, 19-1902

Michael Triplett was tried for being a convicted felon in possession of a firearm under Iowa Code § 724.26(1).
Jury was instructed on two alternative theories: (1) Triplett (principal) had dominion and control of the firearm, or (2) Triplett aided and abetted someone else who knowingly had the firearm.
The jury returned a general guilty verdict; Triplett appealed, challenging only the sufficiency of evidence for the principal/dominion-and-control theory.
Iowa Code § 814.28 (effective July 1, 2019) requires an appellate court to affirm a general verdict if at least one of multiple theories submitted to the jury is supported by substantial evidence. Trial and judgment occurred after the statute’s effective date, so it applies.
The court concluded Triplett waived any challenge to the aiding-and-abetting theory by not arguing its insufficiency on appeal and by failing to preserve that theory in a motion for judgment of acquittal; therefore the unchallenged theory sustains the conviction.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Sufficiency of evidence to support conviction given jury’s alternative theories	State: At least one jury theory (aiding and abetting) is supported by substantial evidence, so the conviction must stand.	Triplett: Evidence insufficient to show he had dominion or control of the firearm (principal theory).	Affirmed: Because the aiding-and-abetting theory (unchallenged) is supported, §814.28 mandates affirmance.
Applicability of Iowa Code § 814.28	State: §814.28 applies because trial and judgment occurred after the statute’s effective date.	Triplett: (did not contest application).	Held: §814.28 applies and requires affirming a general verdict if any submitted theory is sufficient.
Preservation of challenge to aiding-and-abetting theory	State: Defendant did not preserve challenge by motion for judgment of acquittal and did not raise it on appeal.	Triplett: (did not argue or preserve this theory)	Held: Challenge to aiding-and-abetting is waived/unpreserved; appellate review confined to arguments raised.

State v. Klawonn, 609 N.W.2d 515 (Iowa 2000) (statutory use of "shall" creates mandatory duty)
State v. Adney, 639 N.W.2d 246 (Iowa Ct. App. 2001) (issue may be deemed waived if not briefed on appeal)
State v. Truesdell, 679 N.W.2d 611 (Iowa 2004) (insufficient-evidence claim must be preserved by motion for judgment of acquittal)
Hyler v. Garner, 548 N.W.2d 864 (Iowa 1996) (appellate review confined to propositions relied upon by appellant)
In re P.L., 778 N.W.2d 33 (Iowa 2010) (court may affirm if substantial evidence supports any one ground among multiple)
State v. Damme, 944 N.W.2d 98 (Iowa 2020) (date of judgment of sentence controls applicability of statutory amendments)