Authorities say a 33-year-old man arrested in a double homicide last Thursday killed his mother and sister-in-law before he was arrested. Authorities continue the search for answers in the April 9 killing of the two women in the Brownstown area. 33-year-old Edward Robinson faces murder charges in Yakima County Superior Court. He's being held in the Yakima County jail. The two women have been identified as 50-year-old Maria Martinez and 23-year-old Shante Barney.
Yakima County Sheriff's Detectives say an argument between Robinson and the two ladies lead to him using a folding knife to fatally stab both women. A Yakama Nation officer was the first to arrive on the scene. He found Robinson sitting on a couch bleeding from cuts to his hand. He was sitting next to his mother who had already died. Robinson is being held in the Yakima County jail as he awaits an appearance before a judge in Yakima County Superior court.