Ideas for Plot line

Our plot is based around a death that happens in a time before the film is set. The death is of a young girl who was murdered by a group of friends, who got away without any punishment as the death was deemed an accident. But now the older brother of the girl who was killed is set on getting his revenge against this friendship group. This is supposed to be the first time he has murdered somebody as he is still only a teenager, but the audience will want to find out whether he goes on to kill again, whether he gets caught and find out why he is committing these acts of murder on young girls.