Pennsylvania police officer charged with voluntary manslaughter of unarmed man

A Pennsylvania police officer has been charged with voluntary manslaughter after he shot and killed an unarmed man near an amusement park last month.

Jonathan Roselle, 32, of the South Whitehall Township Police Department, had been monitoring traffic near where the July 28 shooting took place -- across the street from Dorney Park & Wildwater Kingdom in Allentown, Pennsylvania -- when a woman pulled up alongside him and told him that a man had tried to enter her vehicle, Lehigh County District Attorney Jim Martin said in a news conference Tuesday.

Roselle then encountered a bleeding man walking on the street, and the man banged on his car and jumped on the hood, Martin said. After that, Roselle reported the incident over radio -- saying that the man may have mental issues -- and issued several commands for the man to get off the vehicle and step away.

The man then walked away from Roselle's vehicle but turn around back toward him. Roselle, who had exited his car, ordered the man to get on the ground. As the man came closer, Roselle fired five shots before calling for help on the radio, Martin said.

The man -- identified by the district attorney's office last week as 44-year-old Joseph Santos of Hasbrouck Heights, New Jersey -- was later pronounced dead at the hospital.

There was no evidence that Santos had a weapon, Martin said.

Cellphone video taken of the shooting and posted to Facebook shows Roselle ordering Santos to get on the ground as he walks toward the police SUV. Santos then appears to put his hands in the air, but as he continues to move toward the officer, Roselle fires five shots at him, dropping Santos to the ground.

After the shooting, Martin said Santos was interfering with traffic and causing damage to cars on US Route 22 and that Roselle "unfortunately" had to use his weapon.

Authorities do not believe that the shooting was racially motivated but rather that Roselle is an "inexperienced officer."

Roselle had just been sworn into the police department in December and had 14 weeks of training after that, according to the department's Facebook page.

Roselle is an Army veteran who served in Afghanistan and is currently a major in the National Guard, The Associated Press reported. The officer, from Parryville, Pennsylvania, had been on patrol by himself for less than five months and is now on paid leave, according to the AP.

Roselle's attorney, Gavin Holihan, said in a statement that Roselle believes his actions were "justified and appropriate" given the circumstances.

"Police officers face challenges every shift that may require split second decisions," the statement read. "Those decisions are then calmly reviewed, with 20/20 hindsight, by the criminal justice system, those in political office, the media and the public."

Rosselle turned himself into authorities on Tuesday and was expected to be arraigned that afternoon. It's unclear if he entered a plea.

Neither the South Whitehall Township Police Department nor the Pennsylvania Order of Police immediately responded to ABC News' request for comment.

ABC News' Joyeeta Biswas, Alexandra Faul and Sofia Grimsgard contributed to this report.