I'm Alice Brennan, this is Background Briefing. And before we start this week's story I want you to know that we're going to some pretty grim places, including discussions of suicide and murder. If it raises any issues for you, contact Lifeline on 13 11 14, and if you need to speak to someone about domestic or family violence, call 1800 RESPECT, that's 1800 737 732. Almost every three months, for the last 15 years, a person with disabilities in Australia has been killed by their carer. That's not a number that's easy to come by here at Background Briefing we've discovered this by poring over court records and media coverage and doing the maths ourselves. A carer is a family member or a friend, with responsibilities for someone else's care. One person with disabilities killed almost every three months is high, but because in some cases disability may not be reported publicly, the true figure is almost certainly much higher.