Stealing other pupils property in the class

In our class there is a boy who always steals other pupils properties. He always wait for everyone to go outside and steal whatever he likes even it is a pencil, textbook, food or even exercise books.
One day as he was doing this I found him stealing an English textbook. When he saw me he start pretending that he was looking for his pencil but I knew it very well that he was just lying to me. 
I went to the head teacher and reported him and the boy was chased out of the school. 

Location: , Soweto/Bahati , Nairobi