Follow KDKA-TV: Facebook | Twitter

PITTSBURGH (AP) – The district attorney says Pittsburgh police are hindering his investigation into a homeowner who was fatally shot by officers responding to a home burglar alarm.

READ MORE: Local Police Departments Team Up To Enforce Pedestrian Traffic Laws

Police have said officers shot 57-year-old Christopher Thompkins after someone fired in their direction as they arrived at the front door about 4 a.m. Jan. 22. Thompkin’s ex-wife, who was staying with him at the time, says Thompkins grabbed her gun to chase away an intruder toward the front door.

READ MORE: Just Hanging Out: Butler County Man Twice Catches Bear On Camera In His Yard

Allegheny County District Attorney Stephen Zappala Jr. says police “unilaterally” changed their relationship with his office and didn’t give his investigators timely access to the shooting scene.

Public Safety Director Wendell Hissrich says that’s not true but that there has been “ongoing dialogue” between police and the DA’s officer about how to improve their relationship.

MORE NEWS: Pennsylvania Ending Extended Jobless Benefits, Unemployment Rate Falls Below 5%

(Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)