David John Birnie (16 February 1951 – 7 October 2005) and Catherine Margaret Birnie (née Harrison) (born 23 May 1951) were an Australian couple from Perth, Western Australia. They murdered four women ranging in age from 15 to 31 at their home in 1986, and attempted to murder a fifth. These crimes were referred to in the press as the Moorhouse murders, after the Birnies' address at 3 Moorhouse Street in Willagee, a suburb of Perth.