A 22-year-old Colombian man was arrested Sunday by Costa Rican police for allegedly threatening to stage a terror attack at an Ariana Grande concert in Alajuela.

Costa Rican prosecutors said in a statement that the man, Caicedo Lopez, made credible threats online in Arabic and police reacted, reports La Nacion. The concert was staged without incident.

Speaking with the Costa Rican newspaper, the young man’s grandmother painted a different picture. “If you see him, he is a very shy person, he does not smoke or smoke, he does not go to parties, he does not go to concerts, he is very homely, he is a good boy, very calm. Which happened to me, but it was a joke, even innocent, of a person who is very calm. But he will be responsible for his actions and his mistake. He told me that he never thought that this would become such a big deal, because he simply saw it as something vacillating, like something for the moment. He is frightened by the mistake he made.”

Twenty-two people were killed and dozens were injured when a man set off a bomb at an Ariana Grande concert in Manchester.