This lad maybe just asking a question. If the threat is serious, however, there are many areas in the world where the threat of being killed is always a risk;especially for teenagers who may get involved with drugs. There are a few areas like that here in England! Even more so in other parts of the world. In these sorts of areas it is often just as dangerous to go to the police; perhaps more so.
If mushrome is really threatened he should talk to his parents, or even grandparents.
Magic, I'm afraid, is no defence in such a situation. And even a riot shield (yes, I know it was a joke) will not stop a bullet.