I was intrigued by the subtitle of this, schoolboy poisoner, I hadn't heard of Graham Young before so wasted to learn more about him.
The whole story was rather a complex case and rather in a way motiveless as Graham admitted his stepmother wasn't abusive so it seems as if the poisoning of her, his first victim was pure curiosity as to the effects of poison.
Then just like other serial killers starting out he went onto bigger crimes...