why me wrote:Mental illness is a terrible thing. Might I also suggest that this defense was used as a plea for insanity? But the court did not buy it. And most likely, the whole thing was revenge.
Murderers often use god or the devil for their own purposes.
If you read Under The Banner of Heaven you will discover that both of the Lafferty brothers are perfectly sane in the clinical sense. They are not crazy in any medically defined way, unless you consider the religious delusions known as "faith" and "personal revelation" to be mental illnesses.
Trying to sweep the Lafferty's crimes under the rug using the "mental illness" angle doesn't square with the facts. They are sane men who honestly believed God commanded them to kill a mother and her child, and still believe it fervently to this day.