The federal government (plaintiff) charged Jesus Alvarez-Ulloa (Ulloa) (defendant), a Mexican citizen and former long-time boxer, with violating 8 U.S.C. § 1326(a) by being found in the United States after having been deported. The federal district court trial evidence established that Ulloa was deported in December 2010, that sometime thereafter he knowingly reentered and remained in the country, and that he was found and arrested in Arizona in October 2011. Ulloa asserted an insanity defense and introduced evidence that, as a result of his boxing injuries, he suffered from brain damage that rendered him unable to understand the illegal nature of his presence in the United States. The judge instructed the jury that even if they believed that Ulloa was insane when he reentered the country, they must convict Ulloa if they found that he thereafter regained his sanity long enough to understand the wrongfulness of his reentry and to voluntarily depart from the country. The jury found Ulloa guilty. On appeal to the Ninth Circuit Court of Appeals, Ulloa argued that the judge erred in giving his insanity-defense instruction.