On November 4, 1982, Dunne's daughter, the young actress Dominique Dunne, best known for her supporting role in the blockbuster film Poltergeist, was killed by her ex-boyfriend John Thomas Sweeney. Dominique had left the abusive Sweeney and refused to reconcile with him, leading to a confrontation in which he strangled her in her driveway. She lapsed into a coma and died five days later. Dominick Dunne was a fixture at the trial of his daughter's killer, keeping a journal of the proceedings. Sweeney was convicted of voluntary manslaughter but was only sentenced to 6 ½ years. He was ultimately released after serving only 4 ½ years. Dunne's journal formed the basis of "Justice: A Father's Account of the Trial of his Daughter's Killer," subsequently published in Vanity Fair. The judicial system, Dominick felt, had failed his daughter and sparked in him an interest in justice that would last the rest of his life.