ROCKLAND — A judge has thrown out the confession made to police by a 35-year-old Rockland, Maine, man charged with killing his ex-girlfriend in 2010.

Justice Jeffrey Hjelm ruled Thursday that the confession can’t be used at trial because investigators didn’t stop questioning Arnold Diana when he asked them to do so. The judge is allowing other evidence, including a bloody pillow sheet.

Assistant Attorney General Lisa Marchese told the Bangor Daily News  that the ruling won’t have a significant impact on the state’s case.

Police say Diana strangled 47-year-old Katrina Windred of Friendship in his apartment Nov. 20, 2010, while her 11-year-old son sat outside reading comic books in her car. Her body was dumped on the outskirts of town, where it was found by a man walking his dog.