5 Young Murderers (14 Years Old and Younger)

4.Graham Young
A smart young man fascinated with poisons. Living with his uncle and aunt, the family were constantly getting sick from an unknown origin. Thinking that some mysterious bug has spread to even people in his school, no one suspected him. It was later known that he has been experimenting on them and taking meticulous notes on the dosage he used and their reactions to his poison.

But one day, at the age of 14, his stepmother died and his aunt became suspicious. Months later, he confessed his attempted murder on people around him. Of course he was then institutionalized but he never stopped with experimenting with poison. Because after his release he went on to poisoning 70 more people which killed 2 out of them.

He later lived his life in prison until the first of august in the year 1990, where he died a month before his 43rd birthday.