Crime Philadelphia Police Officer Who Fatally Shot Unarmed 12-Year-Old in Back Charged with Murder: D.A. “He knew the 12-year-old, 5-foot tall, 111-pound Thomas Siderio no longer had a gun and no ability to harm him, but he fired a shot through his back nonetheless that killed him,” D.A. Krasner said By Olivia Jakiel Olivia Jakiel Instagram Associate Editor, Nights – PEOPLE People Editorial Guidelines Published on May 2, 2022 10:16 PM Share Tweet Pin Email Photo: GoFundMe A former Philadelphia police officer has been charged with murder after fatally shooting an unarmed 12-year-old boy in the back in March, Philadelphia District Attorney Larry Krasner announced on Monday. "Philadelphia's 31st Investigating Grand Jury issued a presentment recommending that former Philadelphia Police Officer Edsaul Mendoza be charged with the following crimes for the fatal on-duty shooting death of 12-year-old Thomas 'TJ' Siderio that occurred on March 1, 2022: Murder of the First Degree, Murder of the Third Degree, Voluntary Manslaughter, Possession of an Instrument of Crime," Krasner wrote in a news release. PEOPLE's request for comment from the Fraternal Order of Police Lodge 5, the association that is reportedly providing an attorney for Mendoza, was not immediately returned. In a statement to The New York Times, Fraternal Order of Police Lodge 5 president John McNesby said that Mendoza, "like every other citizen, is entitled to due process, and we are confident that our judicial system will protect this officer's constitutional right to a fair trial." Mendoza, 26, was one of four undercover officers inside an unmarked police car on the night of March 1 when they pulled up to Siderio and another teen, identified as 17-year-old "NK," Krasner said in a press conference Monday. After officers approached the two boys for allegedly riding their bikes the wrong way down a street, T.J. then "likely" fired at the vehicle and a bullet entered the rear window. The presentment — or formal charging document — noted a Philadelphia police directive that says "plainclothes" police officers are not supposed to make routine traffic stops "unless the actions of the violator are a clear danger to pedestrian or vehicular traffic and no marked unit is readily available." While three officers took cover, Mendoza began "what can be fairly called a tactically unsound foot chase" of T.J. as another officer fired a shot at nothing in particular, Krasner said in the press conference. Want to keep up with the latest crime coverage? Sign up forPEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. Mendoza fired a total of three shots while pursuing T.J., including once at the end of the block where the foot chase began while "standing on the sidewalk — and relatively close — to Thomas Siderio." Citing audio and video footage shown to a grand jury, Krasner said Mendoza knew the boy was unarmed when he fired the fatal shot, as it appeared Siderio complied with demands to drop the gun and get on the ground. "At the time of the last two shots, Thomas Siderio was unarmed, having discarded the gun back at 1739 Barbara Street, which was approximately 40 feet away from where Thomas Siderio was chased and then shot," Krasner said, adding that it "was certain" that the boy had stopped running and was "possibly surrendering." Krasner also said it was "certain that Thomas Siderio, at the time he was shot, was essentially face down on the sidewalk." "The gun was sitting on the street below the curb line nearly 40 feet away," Krasner continued. "Thus, when Officer Mendoza fired the third and fatal shot, he knew the 12-year-old, 5-foot tall, 111-pound Thomas Siderio no longer had a gun and no ability to harm him, but he fired a shot through his back nonetheless that killed him." "The investigation into this terrible tragedy remains ongoing. As in all cases, the Philadelphia District Attorney's Office intends to prosecute this matter thoroughly and even-handedly. Our office has no further comment at this time," the news release from the D.A. office stated. A GoFundMe for Siderio has raised over $5,500 for the family since his death.