I'm 15, a classmate is threatening me. Adults don't believe it. What to do?translated

Reader question:
Hello. I'm 15. I have a classmate, we live in a city with a population of 14k. I have been friends with this boy and my friends since childhood. Since the 8th grade, everything has changed dramatically, he stopped communicating with the class, he walks alone, withdrawn and quiet, we continue to communicate at school. During class, he constantly breaks off my friend’s fingers, pinches them, and says that he is an anti-pacifist. A friend said that he sent her stickers with disfigured people, buys knives, jokes about violence and murder, said that he will kill and eat us, and wants to get rid of someone. He says this whole topic is very cool. He told his girlfriend that when he gets rid of her, he will put other terrible things in the guitar case. Today I laughed at the tragic death of a priest. Words cannot express my emotions every day, especially when he said that he did not guarantee that I would make it home. I don’t know what to do anymore. I pray, but I live in fear. Help please. Adults don't believe it.
Daria
Priest's answer:
Archpriest Andrey EFANOV
God bless you, dear Daria!
There are situations when jokes and games end and you need to act in an adult and serious way.
Your classmate makes direct threats: kill, get rid of...



