An Upper Pottsgrove police officer was charged Tuesday with manslaughter and related crimes in the shooting death of a college student that prosecutors said was unjustified.

Corporal Sean Farrell, 58, shot Glenwood Pysher IV on Aug. 23 after Pysher accidentally knocked on the door of the wrong house after a night out drinking with friends. The residents, thinking Pysher was trying to break in, called police, authorities said.

Montgomery County District Attorney Kevin Steele said Pysher was not a threat, and that Farrell’s use of force was not legal.

Farrell, who has served as an officer in Upper Pottsgrove since 2005, has been placed on administrative leave. He is a third-generation police officer, according to an interview he did with the Reading Eagle.

Pysher, 22, affectionately known as “Bubba,” was days away from returning to St. Elizabeth University in North Jersey for his senior year. He had a made a wrong turn while walking to a friend’s house, and didn’t realize he was at a stranger’s door, said his mother, Erin.

Minutes later, Farrell responded to a 911 call reporting an attempted break-in, and shot Pysher two times, killing him instantly. Pysher’s family said just three minutes elapsed between the initial 911 call and the shooting.

The Montgomery County Coroner’s Office ruled the death a homicide.

In the days after the shooting, Pysher’s family expressed sadness and outrage and said they wondered why the officer didn’t take steps to de-escalate the situation.

“It was a senseless loss, and it shouldn’t have happened,” Erin Pysher said in an interview. “I don’t know what the officer was thinking or doing that his first response was to shoot an unarmed kid.

“This was all a huge mistake, and they killed him.”

This is a developing story and will be updated.