Start studying And Then There Were None-Who Did They Kill. Learn vocabulary, terms, and more with flashcards, games, and other study tools. * If you are referring to the Justice Wargrave in "And Then There Were None", his motive was simply to bring justice to the murders where the "murderers" had gotten of Scots-free. Correct! The killer was Justice Lawrence Wargrave. How did justice wargrave kill himself? One little Indian boy left all alone; He went and hanged himself and then there were none. It was first published in the United Kingdom by the Collins Crime Club on 6 November 1939, as Ten Little Niggers, after the minstrel song, which serves as a major plot point. He wanted to kill people who had committed crimes that were untouchable by the law. And Then There Were None is a mystery novel by English writer Agatha Christie, described by her as the most difficult of her books to write. *SPOILER ALERT! Answer. Justice Wargrave is the murderer Ever since he was a child, Justice Wargrave has had a … Wiki User 06/05/2012.