The insanity defense is one of the oldest defenses in the book. Recently, it was used by Elzbieta Plackowska. She was accused of stabbing her son (5) and daughter (7) to death in 2012. The court rejected her defense. It found her guilty and sentenced her to life without parole. The legislation on this has specific requirements.
A mother killing her own young children is an unusual crime. But, that does not automatically mean it can only occur because someone is insane. Illinois has strict requirements for accepting this kind of defense. They include a mental assessment by a competent person with the right qualifications and experience.
Key Thing to Consider for Review in the Insanity Defense