I pointed out that dot inside the circle years ago over on ZKF, but was ridiculed,and shrugged off. Most people thought it was a knot or imperfection in the wood of the desktop. I am not sure if they are right,but it certainly looks like the cipher symbol

Hi Morf, this is one of the reasons why we’re here and not there

If the story connects then he was already engaged in the cipher stuff at school.

I suspect he became interested in the cipher stuff around the time he attended the school, but how exactly? He found out he was quite good at it (or wanted to be) and started experimenting with some of his early fantasies. Carving ciphers in desktops which could possibly reveal some of these fantasies as some expression of guilt or thrill. These fantasies then grew and developped and eventually lead to the string of killings and communications we know so well.