How can Not Guilty by Reason of Insanity and Guilty but Mentally Ill exist in the same legal system?
<p>I was reading about the two types on insanity pleas, known as '<em>NGRI</em>' (Not Guilty by Reason of Insanity) and '<em>GBMI</em>' (Guilty But Mentally Ill).
For example, a good excerpt <a href="https://books.google.com/books?id=OsfI9dAVFvcC&amp;pg=PA231&amp;lpg=PA231&amp;dq=why%20plead%20guilty%20but%20insane&amp;source=bl&amp;ots=ZRL1caBcmT&amp;sig=4oOYInHqvlx4YrDy6ghTVc_IHis&amp;hl=en&amp;sa=X&amp;ved=0CC8Q6AEwAzgKahUKEwjKhaiYzrnHAhXJ2T4KHSM4Ddg#v=onepage&amp;q=why%20plead%20guilty%20but%20insane&amp;f=false" rel="nofollow noreferrer">is here on Google Books.</a></p>
<p>However, something very obvious is bothering me:</p>
<p>How can you have a legal system where on one hand we consider insane people not guilty of their crimes and on the other say that they <strong>can</strong> be guilty? Isn't it a contradiction?</p>
<p>If insanity is a valid &quot;excuse&quot; to escape responsibility for a crime, then why isn't it always a valid excuse? Why would we allow insane people then to be found guilty? We already acknowledge in our legal system that insane people are not at fault.</p>

<p>There is a clinical difference between insane and mentally ill. </p>

<p>An insane person is "so irrational in their behavior, or so unable to control it - so unlike 'us'" that they are not criminally liable (from earlier in the chapter).</p>

<p>Mental illness is "substantial disorder of thought or mood that substantially impairs judgement ..." (from near your link).</p>

<p>Clearly this is a subtle clinical distinction and will hinge on the expert evidence and the applicable law.</p>

criminal-law trial legal-concepts plea insanity