Cpl. Sean Farrell, 58, is charged with voluntary manslaughter, the district attorney's office announced Tuesday.
Glen Pysher IV, 22, died after he was shot twice in the chest in the early morning hours of Sunday, August 23.
D.A. Kevin Steele said during a news conference that Pysher had been out drinking with his friends when the entire group was driven to a home by a designated driver.
Pysher decided to walk to another friend's house about a half-mile away, Steele said, but became confused and went to the wrong home.
Pysher started banging on the back door of the home on Snyder Road, Steele said, and the homeowners inside called 911.
Cpl. Farrell was the first officer to arrive on the scene, Steele said.
According to investigators, Farrell approached the scene with his service weapon drawn, using its mounted light for illumination, and he took a position behind a red car.
His body-worn camera shows Farrell telling Pysher to put his hands up and drop to the ground, Steele said.
In a still image from the video released by the D.A.'s office, Pysher can be seen with his hands up.
Pysher continues walking toward Farrell, Steele said, and Farrell again yells at Pysher to drop to the ground.
Pysher continues walking toward him, and Farrell yells, 'Stop, or I'll...' and fires his weapon before finishing his sentence, Steele said.
Pysher fell to the ground about 17 to 20 feet away from where Farrell was standing, according to investigators.
Immediately after the shooting, Steele said Farrell's backup arrived on the scene, and Farrell can allegedly be heard on the body camera saying, "the guy [expletive] charged me, screaming and yelling, and wouldn't get down on the ground."
Steele said the video does not show Pysher charging at Farrell, nor does it show him either yelling or screaming.
Pysher was not armed with any weapons, Steele said, who also noted that Farrell had other options available to him, including a Taser and an expandable baton.
Steele outlined the circumstances in which police officers are allowed to use deadly force, and said this shooting did not meet any of those criteria.
"As the District Attorney, it is my role under the law to evaluate the totality of the circumstances of any fatal shooting by police and to determine whether that use of lethal force was justified under the law," said Steele. "The investigation found that Cpl. Farrell had less-than-lethal options on his utility belt that he did not employ, including a taser. At the time of the shooting, the officer was a safe distance from Pysher behind a car, and the victim had his hands in the air and did not possess any type of weapon. Mr. Pysher was not a threat. This is not a legal use of deadly force, leading to the charge of Voluntary Manslaughter."
Farrell has turned himself in to Montgomery County detectives, Steele said. Bail will be set at the arraignment, which is expected later Tuesday.