This vlog - courtesy of Peaked Interest - is the most balanced and informed contribution that I've come across on this case. The commentator explains the actions of both the police and the judges (to my satisfaction at least). His explanation for the sister's behaviour falls on amphetamine abuse leading to psychotic episodes - and he accounts for how this could have not been detected:
I must say though - of all the incidents chewed over on this site this one has to be the most solidly `Fortean`. By this I don't mean that I necessarily subscribe to the rogue supersoldier conspiracy explanations (although the case seems to beg for them) but just that the whole thing represents an extremely unusual combination of events.
Also, of course, we must never forget that at the core of it all is a terrible, terrible tragedy: the violent death of a well-intended man.