Elements of insanity as an exempting circumstance

Dear PAO,

My brother was attacked by his neighbor and could have died without timely medical intervention. A criminal case was filed, and the relatives of the accused claimed that he was insane. They presented a psychological evaluation conducted five months after the hacking incident. Allegedly, the defense of insanity would surely result in the dismissal of the case. Is the evaluation report sufficient to absolve the accused from the crime charged?