HARRISBURG, Pa. — Authorities say a deputy U.S. marshal shot and killed while serving a warrant in Pennsylvania was struck by a bullet fired through a wall by a fellow officer and not by a gunman who opened fire on police.

Dauphin County District Attorney Fran Chardo said Thursday that conclusion was made after laboratory tests were performed on material related to the Jan. 18 death of Deputy Marshal Christopher Hill.

Chardo says 31-year-old Kevin Sturgis fired the first shot and that police were justified in shooting him to death outside the home in Harrisburg.

At the time, The Associated Press and other news outlets reported it was a bullet fired by Sturgis that killed the 45-year-old Hill. The U.S. Marshals Service says ballistics and forensics contradict those initial indications.