I guess he is what is known as a psychopath or sociopath - they have no feelings for anyone except themselves, will do anything to achieve their ends and it was certainly premeditated. Not sure these people ever change so hope he stays locked up for many years.
I don't understand why people aren't identified, even children. If they are dangerous and have a history then the public need to be kept informed! There might be other crimes that haven't yet been attributed to them and a lack of transparency could prevent this happening?