An 18-year-old man is under arrest for fatally shooting a Temple University police officer — and trying to rob him as he was on the ground bleeding —, officials said Sunday.

Miles Pfeffer, 18, was arrested Sunday morning for murder, the Bucks County district attorney’s office said.

He was also charged with murder of a law enforcement officer, robbery, carjacking and weapons crimes in the death of Officer Christopher Fitzgerald, the Philadelphia district attorney’s office said.

Fitzgerald, 31, had been trying to stop a carjacking around 7 p.m. Saturday night when he was shot in the head, prosecutors said. Security video caught the entire incident, KYW-TV reported.

Fitzgerald tried to stop three robbery suspects, but Pfeffer allegedly ran instead of halting. Fitzgerald caught up to the youth, according to WTXF-TV, which obtained surveillance footage. They were seen scuffling as Fitzgerald repeatedly ordered Pfeffer to the ground.

Instead, Pfeffer shot him, then stood over the officer and fired several more times, a WTXF reporter wrote on Twitter.

“Pfeffer is also alleged to have attempted to rob Officer Fitzgerald of his gun and to have gone through his pockets, while the officer was laying on the ground and fatally wounded,” District Attorney Larry Krasner said in a Sunday statement.

“Pfeffer is further alleged to have committed a carjacking a short time after, close to the location of the officer’s murder.”

The slain cop’s father was Joel Fitzgerald, a 17-year Philadelphia Police Department veteran and the former chief of police in Allentown, Pa. The elder Fitzgerald had also served as chief in Fort Worth, reported WFAA-TV, and that police department also issued a statement of condolence. Joel Fitzgerald is currently Chief of Police and Emergency Management at the Regional Transportation District in Denver, Colorado, The Morning Call reported.

“I am heartbroken to inform you that Temple University has lost a first responder and hero to senseless gun violence,” Temple President Jason Wingard said in a statement. “There are simply no words that can make sense of this tragedy. It tears at our sense of community and safety. We all mourn this unspeakable loss.”

“Officer Fitzgerald gave his life to selflessly serve and defend this community,” Temple vice president for public safety Jennifer Griffin said in another statement. “The courage and bravery he displayed highlights the day-to-day sacrifice made by our Temple University Police Officers to keep our community safe. This loss leaves an enormous hole in all of our hearts. He was a father, a husband, a son, a colleague, and a friend.”

“It just shakes everybody to the core,” Temple official Ken Kaiser told the Philadelphia Inquirer.

Pfeffer was reportedly picked up just before 7 a.m. Sunday at his family’s Buckingham Township home, the Bucks County district attorney’s office said. Local real estate website Redfin has the house valued at $1.2 million.

“Police used the fallen officer’s handcuffs in placing the suspect under arrest,” prosecutors noted.

The Temple University Police Association created an online funding drive for Fitzgerald’s family that had raised more than $80,500 of its $150,000 goal by 7 p.m. Sunday.

“Officer Fitzgerald was a loving husband, father, friend, and public servant whose dedication to his family and community was unmatched,” the organizers said. “Officer Fitzgerald loved being a police officer, and he will always be remembered for his fearlessness in fighting crime and his compassion for his community.”

With News Wire Services