Dear Sir and Madam, you're son is a homicidal mainiac and a murderer. Any questions?
to be honest, if this were really a war - his family members would have been taken away for questioning. intense questioning.
the questions will continue from there...
Who are your friends, his friends, the friend's friends, ad infinitum.....
It's a good starting point. The family should suffer, just like the families of the victims.