In July 2013, Amos Wells killed his pregnant girlfriend and their unborn child, as well as his girlfriend’s mother and younger brother. More than three years later, in November 2016, he was convicted of capital murder, and the sentencing phase of his trial began.
In Texas, where the murders and Wells’ trial took place, jurors weighing whether to impose the death penalty are asked to consider the “probability that the Defendant [will] commit criminal acts of violence” in the future and “sufficient mitigating circumstance[s]” from the defendant’s life that may justify imposing a sentence of life without parole instead. Defense attorneys can call witnesses to address these considerations, such as mental health experts or a defendant’s loved ones.
During the sentencing phase of Wells’ trial, his legal team called one such witness to discuss Wells’ genetic makeup. The genetic expert described a mutation in Wells’ Monoamine Oxidase A gene that leads to reduced metabolism of serotonin, explaining that, when combined with the “semi traumatic environment” that Wells grew up in, this gene mutation “contribut[ed] to ‘a greater likelihood that [Wells] could have explosive and violent outbursts in his lifetime.’” In a memorandum, Wells’ counsel acknowledged that this testimony could backfire if it appeared to confirm that Wells posed a continuing threat to society, but said the goal was to “diminish[] his perceived culpability” by highlighting factors he couldn’t control that may have led to the murders.
On Nov. 18, 2016, the jury sentenced Wells to death. He’s spent much of the past nine years challenging this sentence and his conviction, although with little success. In July 2025, the U.S. Court of Appeals for the 5th Circuit denied his request for a certificate of appealability based on his legal team’s decision to have the genetic expert testify. Wells contends that the team’s decision was misguided enough to violate the Sixth Amendment’s guarantee of effective assistance of counsel, and he’s asked the Supreme Court to weigh in.
In his petition for review, Wells’ current legal team called the genetic expert’s testimony “devastating.” To avoid a death sentence, they explained, Wells needed “to convince the jury that evidence of his future dangerousness was outweighed by evidence of mitigation.” Instead, “the defense’s own expert testified, based on debunked science, that petition had a genetic ‘defect’ that made him many times more likely than others to commit violent offenses.”
The petition acknowledged that the Supreme Court has previously recognized that a defense team can concede guilt in a capital trial when doing so can “reasonably be expected to yield corresponding strategic advantages for the defendant at sentencing.” But no such advantages were present in this case, Wells’ team contended.
In their brief opposing Supreme Court review, Texas officials argued that the 5th Circuit was correct to deny Wells a certificate of appealability. Wells’ legal team’s “informed decision” to have the genetic expert testify, they wrote, was part of a “substantial mitigation case that centered on the traumatic nature of Wells’s upbringing,” not a concession of his “future dangerousness.” Texas officials further argued that Wells’ case is not worthy of the court’s time because it raises “no conflict among the courts of appeals, no departure from accepted and usual judicial standards, and no important question of federal law” warranting the court’s intervention.
In his reply brief, Wells’ legal team emphasized that even “strategic” decisions by counsel can be scrutinized under the Sixth Amendment. “Respondent quibbles about whether the evidence amounted to a concession [of dangerousness], but for confirmation one need look no further than the prosecution itself, which repeatedly and vigorously argued to the jury—without contradiction from the court—that it could find future dangerousness based on petitioner’s evidence alone.”
The petition for review in Wells v. Guerrero is scheduled to be considered by the justices for the first time at their private conference tomorrow.