April,,this would be down to us to do a general overall look at the case,,starting with how he passed the polygraph test with " flying colours " as was described,,,,,along with him getting past 27 psychiatrists/doctors/professional health-workers in finding him " of sound mind ",etc etc.
A psychopath who has slipped through the net-------------as many do,,or an extremely clever man who can hide the fact such as Shipman did ?
Then you have the likes of Pistorious who breaks down constantly.