Munich shooting absorbed my attention as the murderer was a German Iranian teenager. Shortly it is very similar to heart breaking Sandy Hook shooting in US than Breivik shooting in Norway. Both murderers were teenagers and the target also was children. Both made suicide after attack.
I can guess that Munich murderer had social impairments same as Sandy Hook shooter. This kind of social impairments is coming with extreme anger towards children of the same age as they can not compete and suffer bullying. This is very likely that this disorder falls on Autism spectrum.
This type of disorder is dangerous as there is strong revenge thoughts and shall be recognized by educational system as an special disorder among boy teenagers to help them be cured and keep them under protection.
My heart for all the children who were killed in both massacres. and for those who were the first victims, was not able to find a way to escape their horrible mind.