Just my thoughts here. I think the fact he ended his life after this disgusting episode may on balance be the best end result.. there would be an immense amount of hate and frustration should he have been locked up and given the British justice system, he would have been eligable for release one day. A lot of folk would have been baying for his blood and wished to see him hanged and there is already too much hate in our society as it is. It could be construed as the cowards way out but I believe he was totally deranged as it must take a truly scrambled brain which drives someone to take their own life, let alone the lives of those he so randomly killed in this appalling incident. These kind of incidents differ from those pre-meditated form of crimes where the subject has schemed and planned, in those cases there can be only one outcome in my opinion but alas this is denied us.
One can only feel pity and sympathy for those left behind and perhaps, since there is no-one left to point ongoing hatred toward one can only hope it will help them accept the reality of their ghastly situation more readily. Despite the horror and loss, it may to some degree help them as time goes by.