Evidence about what PET scans, MRIs, MRAs and other neuroimaging techniques do or don’t show about convicted murder John McCluskey’s brain damage, and thus his intent to kill, was the topic of two days of testimony in his capital murder trial.
It was just the first of an anticipated six weeks of testimony in the penalty phase of the federal death penalty case, now that jurors have found him guilty of the carjacking deaths of Linda and Gary Haas in August 2010.
The couple was pulled over at a rest stop on Interstate 40 in New Mexico on their way to a fishing vacation in Colorado when they were carjacked for their camper and pickup and then taken to a rural area and shot. Their dogs were freed and then the camper and their bodies were burned.
Prosecutors called law enforcement witnesses to show McCluskey is “eligible” for death by virtue of being at least 18, showing mental intent and three aggravating factors: multiple killings, prior violent felony convictions involving firearms and prior convictions involving other serious offenses.
The defense has focused on the issue of intent, calling experts in neuroscience to show that damage to his brain means he could not have formed the required element of intent.
Prosecutors objected forcefully to the defense notice that it would call seven mental health-related experts during the eligibility phase. In a filing before testimony began, prosecutors said it was irrelevant and an attempted “end-run” around U.S. District Judge Judith Herrera’s order barring evidence or argument that invited the jury to revisit any doubts about the conviction.
The government rested its case after two days, Herrera permitted testimony that goes to the question of intent.
The jury got seminars on brain functioning from Ruben Gur, a neuropsychologist who directs the Brain Behavior Laboratory at the University of Pennsylvania, and Dr. James Merikangas, a neuropsychiatrist whose research has focused on violent behavior and its prevention.
Both found brain abnormalities, including at least one defect the result of a stroke. The parts of the brain affected by the deficits are those that govern emotion and executive function or planning ability.
The trial resumes Tuesday in the eligibility phase, and if the jury unanimously finds prosecutors have proved the statutory factors, the trial will proceed to the final phase where the jury must decide if he should be executed for his crimes.