The mother of Sophie Elliott is backing a new law making strangulation a criminal offence and hopes it will save women's lives. The new crime is part of a suite of family violence changes which come into effect on Monday. Sophie Elliott was stabbed to death by her ex-boyfriend Clayton Weatherston at her Dunedin home in 2008. Her mother Lesley Elliott says in the days before she was killed, Weatherston had held her daughter down and choked her.