Kent Kiehl has spent two decades traveling to prisons with a mobile MRI machine, convinced he can spot the criminal brain. His research on psychopathy in incarcerated populations has become routine evidence in capital cases across America. But the science is far shakier than courtrooms have treated it, and the consequences for defendants have been devastating.
The path to this moment traces back to 2009, when Kiehl testified on behalf of serial killer Brian Dugan in a Chicago courtroom. Dugan was facing execution for the rape and murder of a 10-year-old girl. Using functional magnetic resonance imaging, Kiehl scanned Dugan's brain after assessing him on a psychopathy checklist designed to measure traits like grandiosity and pathological lying. Kiehl told jurors that Dugan's score was among the highest he had ever recorded, and that brain scans showed atrophy consistent with psychopathy. The jury sentenced Dugan to death anyway, though his sentence was later commuted when Illinois imposed a moratorium on executions.
What followed was a seismic shift in American courtrooms. Between 2005 and 2015, brain-based evidence appeared in more than 2,800 judicial opinions. Neurological arguments for reduced criminal responsibility showed up in roughly 10-12 percent of murder trials and about 25 percent of death penalty cases. Overall, 40 percent of serious felony cases referenced brain-based evidence. Defense attorneys, desperate to save their clients' lives, seized on the idea that criminality could be located in biology, that some people were simply wired for violence through no fault of their own.
Critics argue the science doesn't support such claims. The biological argument for criminal predisposition echoes long-debunked eugenic thinking that once influenced American courts and policy. In a country where people of color face disproportionate arrest, conviction, and execution rates, evidence based solely on biological factors raises profound ethical concerns. Even when used by defense attorneys to argue for lighter sentences, brain evidence carries risks: prosecutors have wielded identical logic to demand harsher punishment, arguing that certain individuals will forever be prone to violence.
The case of Amos Joseph Wells III illustrates how far this reasoning has gone. On July 1, 2013, Wells walked into a police station near Fort Worth, Texas, and confessed to shooting his pregnant girlfriend, her mother, and her 10-year-old brother. Video footage showed him weeping in the interrogation room. His court-appointed attorneys contacted Kiehl to scan Wells' brain and conduct genetic testing. Their defense strategy rested on a single idea: that Wells' biology, not his choices, determined his actions. "Amos didn't ask for his genetics, he didn't ask for the brain he got," his lead attorney told jurors in 2016. The jury sentenced Wells to death. His current attorneys argue that the judge prevented jurors from seeing evidence of Wells' genuine remorse, evidence that might have outweighed the neurological arguments for execution.
Kiehl, now 56, grew up a mile from Ted Bundy's childhood home in Tacoma, Washington. His father, a reporter and news editor, covered Bundy's trial. The proximity to such darkness sparked Kiehl's obsession with studying criminal minds. He studied psychology at UC Davis and apprenticed under Robert Hare at the University of British Columbia, a pioneer in prison neuroscience. Hare was initially reluctant to accept him as a student, but Kiehl's persistence won him over. Today, Kiehl directs the laboratory at the Mind Research Network in Albuquerque, which he claims houses the world's largest database of brain scans from incarcerated people.
During interviews between November 2023 and February 2024, Kiehl described himself as an iconoclastic researcher pursuing a cure for criminal violence. He speaks rapidly in a high nasal pitch and boasts that most other psychopathy researchers lack his courage to work in maximum-security prisons. He also invited a reporter to his lab for a brain scan, then rescinded the invitation and refused further comment on the story.
The field of criminal neuroscience remains small and insular, with papers often tracing back to Kiehl's work. Few other contemporary American scientists focus on the incarcerated population. Yet his theories have shaped thousands of cases, fundamentally altering how defendants are sentenced and how jurors understand culpability. What began as controversial research testimony has quietly become standard practice in courtrooms nationwide.
Author James Rodriguez: "Kiehl's work shows how seductive the promise of scientific certainty can be in law, especially when defending the indefensible looks impossible."
Comments