In her closing argument, Elisa Long, a federal public defender representing Mr. Bowers, emphasized that he hadn’t gotten into trouble with the law before the attack. But she, she said, in the previous months, she had « spent an enormous amount of time alone on the Internet absorbing all kinds of vile and extremist content. »
But Mr. Bowers is not pursuing an insanity defense, in which the defendant admits to having committed some criminal act but argues that, due to mental incapacity, he did not fully understand that it was wrong. Insanity defenses are rare, and legislation made such defenses substantially more difficult to make after John W. Hinckley Jr. was found not guilty by reason of insanity in the 1981 assassination attempt on President Reagan.
« Insanity defenses, I don’t care what kind of case it is, it’s extremely difficult to succeed, » said George Kendall, a lawyer who represents people on death row. It would have been especially difficult in this case, several defense attorneys said, with a defendant who seemed outspoken about his hatreds and showed no obvious signs of a debilitating psychosis.
But when it comes to deciding whether someone deserves execution, Kendall said, evidence of serious mental illness can give one or more jurors serious reservations, which may be enough for the defense, since the verdict on the sentence of death must be unanimous.
In 2015, a jury rejected the insanity defense brought up by James Holmes, who killed 12 people and injured dozens at an Aurora, Colorado movie theater, and found him guilty on all charges. The jury then ruled that he had acted with aggravating cruelty and was eligible for a death sentence. But, after a month of testifying about Mr. Holmes’ struggles with mental illness, that same jury was divided on whether to execute him. He was sentenced to life in prison without the possibility of parole.
“While jurors rejected the notion that Mr. Holmes fit the narrow legal definition of insanity,” his public defenders wrote in a 2016 Denver Law Review article, “experts in the case agreed that Mr. Holmes he would not have committed this horrible crime had he not been mentally ill.