By CBS3 Staff

MUHLENBERG TOWNSHIP, Pa. (CBS) — A Muhlenberg Township police officer who shot and killed a knife-wielding man will not face charges. The Berks County district attorney ruled the March 15 shooting death of Stephen Hughes was justified.

It happened at a home on Wagon Wheel Lane after Hughes’ niece called 911 twice.

According to authorities, she told police her uncle was being threatening.

The DA says Hughes later charged officers with a knife inside a bedroom.

An officer tased Hughes, authorities say, but it had no effect.

“Officer 1 fired one shot from his handgun, aimed at the central mass, causing him to fall to the floor with a single-shot wound to the chest,” Berks County District Attorney John Adams said. “The action taken by the officer involved was for protecting himself and his fellow officer. Therefore this was a justified use of force.”

Prosecutors say Hughes’ niece called 911 on the advice of a mental health professional.