PHILADELPHIA (AP) — A fired Philadelphia police officer has been charged with murder in the shooting of a fleeing 12-year-old boy, who prosecutors said Monday was on the ground and unarmed when the officer fired the fatal shot.

Philadelphia District Attorney Larry Krasner announced first- and third-degree murder charges against former Officer Edsaul Mendoza in the shooting of Thomas “T.J.” Siderio on March 1, saying video showed to the grand jury contradicts the officer’s version of events. Police say the youth had first fired a shot at an unmarked police car, injuring one of four plainclothes officers inside.

Mendoza, 26, was also charged with voluntary manslaughter and other charges, according to a grand jury presentment unsealed Monday. He had been suspended from his job March 8 with intent to fire.

Court records show Mendoza surrendered Sunday and was denied bail, rare treatment for former law enforcement officers facing charges.

A spokesperson for the Fraternal Order of Police Lodge 5 said the union plans to provide an attorney for the officer. Court records showed the public defender’s office represented Mendoza at his bail hearing Monday. The defender’s association declined to comment on the case.

New details were revealed in the grand jury documents, including that Siderio had thrown a gun down about 40 feet (12 meters) before he was shot and that he had dropped to the ground, either tripping or obeying a command to get down. Krasner said the officer crossed between two parked cars and, from about half a car length away, fired the fatal shot from the sidewalk behind the youth.

Krasner said much of the evidence was based on the video, which has not been publicly released. According to grand jury documents, prosecutors created a composite video from two cameras, one that recorded clear visuals of the foot chase and another that recorded a different visual angle but caught sound.

“It is certain that (Siderio) had stopped running and he was possibly surrendering … and he was essentially facedown on the sidewalk,” Krasner said, saying the youth was in a pushup position looking back toward the officer when he was shot.

Krasner called the entire foot chase “tactically unsound” and said the video was “disturbing and very difficult to watch.”

There is no indication that race was a factor in the shooting of Siderio, who was white.

Police said the four plainclothes officers were in an unmarked car the night of March 1, looking for a teenager they wanted to interview related to a firearm investigation. They saw two youths, Siderio and an unnamed 17-year-old, and maneuvered the car around the block and next to them to initiate a stop.

Prosecutors said Monday that almost at the same time the officers turned the red and blue lights on, a shot came through the back passenger window and ricocheted around the car. Prosecutors said it was unclear from video whether the boy knew it was a police vehicle when he fired, but the investigation is ongoing.

One officer was treated for injuries to his eye and face caused by broken glass.

Mendoza and another officer on the passenger side got out and fired one shot each. Mendoza then chased Siderio down the block, firing twice and striking the boy once in the back from what prosecutors say was “relatively close range.”

Krasner said Mendoza immediately told another officer that Siderio had thrown his gun and pointed to an area down the street, signaling to prosecutors that he knew the boy was unarmed. Krasner said the video also shows the officer changing his approach and that he was able to see Siderio was on the ground when he fired the fatal shot.

Police recovered a firearm that had been reported stolen, and noted in the days after the shooting that another bullet was in the chamber.

An attorney representing Siderio’s father in a lawsuit against the city and officer would not comment.

Mary Siderio, the boy’s great-grandmother, told KYW-TV she was happy with the news.

“I’m so heartbroken,” she said. “I can’t sleep. None of us can sleep. It’s horrible.”

The presentment notes a handful of contradictions to Mendoza’s account that the boy pointed a gun at him and that he was standing in the street when he fired, rather than almost over Siderio on the sidewalk.

It also raises questions about whether the officers were initiating a traffic stop against the two boys for riding their bikes the wrong way on a one-way street in order to talk to them about the firearm investigation. It notes neither was the target of that investigation. Unmarked cars and plainclothes officers are supposed to make traffic stops only in dangerous circumstances, according to department directives.

“It’s certainly a situation that might have had a very different outcome if there had been a marked police car,” Krasner said.

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