In a significant development, Edsaul Mendoza, a 28-year-old former Philadelphia police officer, admitted guilt to a third-degree murder charge on Friday.

The charge pertains to the 2022 shooting incident that led to the death of 12-year-old Thomas Siderio.

ABC 6 reports that during the incident, Siderio was in the company of an unidentified 17-year-old. The officers approached them in their vehicle to question them in relation to a firearm investigation. The police allege that Siderio fired at their car before fleeing and discarding the weapon.

In response, the officers fired at the boy, after which Mendoza pursued Siderio down the street. He fired two shots at the boy, one of which hit him in the back from a "relatively close range."

Philadelphia District Attorney Larry Krasner, in a press conference, stated that Mendoza was aware that Siderio was unarmed and posed "no ability to harm him" when he discharged the fatal shot.

WATCH AS POLICE PAY EXTRA ATTENTION TO YE'S PRONOUNS

The district attorney's office, speaking to the New York Times, emphasized the importance of impartial justice, stating, "Everyone must be accountable under the law.”

WATCH: WHY IS BIDEN SAYING HIS UNCLE WAS EATEN BY CANNIBALS?

However, Siderio's family expressed dissatisfaction with the plea agreement, arguing that Mendoza should have faced first-degree murder charges. In a statement to ABC 6, Joanne Payne, Siderio's aunt, described the situation as "heartbreaking, earth-shattering, devastating," adding that Mendoza "should be held to a higher standard than you and I."

FELON VOTING RIGHTS: THE CONTROVERSIAL DEBATE SWEEPING MISSISSIPPI'S LEGISLATIVE HALLS

Payne further criticized the handling of the case, stating, "We cannot stand over a child on a city street and shoot them. TJ was on the ground, face down, unarmed. The threat was eliminated." She accused the authorities of painting a "horrendous crime" picture, with the proposed sentencing falling short of justice.

Mendoza, who served on the force for five years, was dismissed a week after the incident. Former Police Commissioner Danielle Outlaw stated that Mendoza's actions violated department policy. Mendoza's sentencing is scheduled for July.