Insanity Defense for Mangione? No

It is being written that alleged murderer Luigi Mangione may be charged in Federal Court in New York. He is alleged to have shot to death the UnitedHealthcare CEO, Brian Thompson. It is being speculated that the defense may use the insanity defense, or some other defense going to an impaired mental state at the time of shooting. They will have an impossible time with that because in Federal Court, the Daubert Standard of Evidence holds sway.

If a forensic psychiatrist and/or forensic psychologist is retained to do an evaluation of Mangione, there is no evidence that they could adduce that would meet the Daubert Standard, and therefore should be excluded. I have yet to meet an expert with scientifically substantiated clairvoyance to reliably determine a person's mental state in the past. If this goes to trial, it will up to the jurors to weigh the facts, and the gatekeeper judge to exclude any unscientific and potentially prejudicial defense psych expert testimony.