On 13 December 2011 , a murder–suicide attack Attack took place Process_start in the city of Liège in the Wallonia region of Belgium .

The prosecution argued Quarreling that , motivated by a large inheritance , Bamber had shot Use_firearm the family with his father 's semi-automatic rifle , then placed Placing the gun in his unstable sister 's hands to make it Causation look like a murder–suicide .