Does a co-defendant's conflicting testimony justify trial severance? State v. Pham Explained

In State v. Pham, the Utah Court of Appeals addressed whether conflicting testimony between co-defendants justifies trial severance, ultimately reinforcing fundamental principles of preservation of error in appellate practice.

Background and Facts
Anh Tuan Pham and co-defendant Semisi Maama were charged with aggravated robbery, aggravated assault, and riot arising from an incident in a restaurant parking lot. Before trial, Pham moved to sever his case from Maama’s, arguing that admission of Maama’s statements would violate his Confrontation Clause rights under Bruton v. United States. The trial court denied the motion, finding that severance was not warranted because the statements did not directly implicate Pham.

Key Legal Issues
The central issue became whether the trial court erred in denying Pham’s motion to sever. However, the nature of Pham’s argument shifted significantly between trial and appeal. Initially, Pham sought severance based on potential Confrontation Clause violations. On appeal, he argued that the joint trial was prejudicial because the co-defendants presented antagonistic defenses—a completely different legal theory.

Court’s Analysis and Holding
The Court of Appeals declined to reach the merits, finding that Pham failed to preserve his antagonistic defenses argument. The court applied the well-established rule from State v. Velarde that defendants must prove their defenses were “irreconcilable and mutually exclusive” to justify severance. Critically, Pham never presented this argument to the trial court, either in his pretrial motions or during trial proceedings.

Practice Implications
This decision underscores the fundamental importance of preservation of error in appellate practice. Practitioners must present all potential grounds for relief to the trial court, as courts generally will not address unpreserved arguments raised for the first time on appeal. When seeking severance, attorneys should comprehensively address all possible grounds—including Confrontation Clause violations, antagonistic defenses, and undue prejudice—in their initial motions rather than developing new theories on appeal.