Fired Philadelphia officer Edsaul Mendoza charged with murder in shooting of 12-year-old Thomas "T.J." Siderio

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. Police say the youth had first fired a shot at an unmarked police car, injuring one of four plainclothes officers inside.

Mendoza 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 of the shooting were revealed in the unsealed grand jury documents Monday, including that Siderio had thrown a gun down about 40 feet before he was shot and that the youth had dropped to the ground, either tripping or obeying a command to get down. Krasner said Monday during a press briefing the officer who shot Siderio knew the young boy was unarmed before shooting him in the back, CBS Philadelphia reports.

Krasner said the officer crossed between two parked cars and, from about a half-car length away, fired the fatal shot.

Krasner said much of the evidence was based on a video that has not been publicly released.

"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.

Krasner called the entire foot-chase "tactically unsound" and said the video was "disturbing to watch," though when pressed he refused to characterize the shooting beyond saying it was clear to him there was evidence to support a first-degree murder charge.

Police said the four plainclothes officers were in an unmarked car on 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's 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 back, signaling to prosecutors that he knew the boy was unarmed. He said the video also shows the officer slowing down and changing his approach, and that he was able to see Siderio was on the ground when he fired the fatal shot.

A message left with an attorney representing Siderio's father and other family members was not immediately returned.

Speaking to CBS Philadelphia, the great-grandmother of Siderio was emotional after hearing news of the charges.

"I'm happy. That's all I can say right now," Siderio's great-grandmother, Mary Siderio, said. "I'm so heartbroken, I can't sleep. None of us can sleep. It's horrible."

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