His family initially hired local attorney John Fahle to represent him, but Gonzalez-Lopez then contacted and hired a California attorney, Joseph Low, to represent him, and the understanding appeared to be that Fahle and Low would work together on his case.

Gonzalez-Lopez then informed Fahle that he wanted Low to be his only attorney, and Low then filed another request to be admitted pro hac vice, which the district court and the United States Court of Appeals for the Eighth Circuit both rejected.

Gonzalez-Lopez went to trial represented by another attorney, Karl Dickhaus, who requested permission for Low to sit with him at the counsel table.

The trial judge denied that request and ordered Low to sit in the audience and not to speak with Dickhaus, enforcing the order by having a federal marshal sit between Dickhaus and Low throughout the trial.

[3] The Scalia opinion reasoned that the refusal to let Low represent Gonzalez-Lopez caused effects that could never be adequately measured for harmless error, because it is impossible to speculate on what the effect that a different attorney and one that the defendant wished to have would have had on the proceedings—including whether a trial would have occurred in the first place.