Killer boy's no genius: A gruesome detail allows him to kill without mercy or remorse

And indeed, the way in which the killer boy planned the mass massacre at the elementary school "Vladislav Ribnikar" leads one to think that he is an above-average intelligent person: he made a floor plan of the school, a list of peers who present "primary targets", Molotov cocktails...
He picked a precise weapon from his father's collection and timed the attack when his class VII/2 was closest to the school entrance and the school policewoman was far away. Can someone who is not far above average, who is not an "evil genius" do all that at just 13 years of age?

Psychological profile of the killer boy

A "Blic" source close to the investigation says that not everything is as it seems at first glance. He makes a shocking claim: according to everything we know so far, the killer boy is, in fact - intellectually average!
"Not a genius at all, as stated. It is possible that he was bothered by the others in class, because he had to, for example, put in more effort in order to achieve the success of one of his victims, or to please his parents who, according to everything we know, demanded impeccable success from him. It can be said that they brought him up spartanly," says the "Blic" source.
As the media reported, the parents of the killer boy were very proud of their "little genius", as they called him, because in addition to his duties at the elite school, he also attended numerous extracurricular activities. He spoke foreign languages, went to an acting school, a music school, practiced sports, won city competitions, was an honors student.
Did so much pressure from hyper ambitious parents leave tragic consequences on the killer boy's psyche? This is supported by the recent statement of Mina Zirojevi, a member of the Council of...