Jonaiki Martinez-Estrella, a gang member convicted of killing 15-year-old Lesandro “Junior” Guzman Feliz in 2018, has died in prison. He was 31 years old.

Documents released by the Department of Corrections and Community Supervision listed him as deceased. Officials said Martinez-Estrella was found unresponsive Friday afternoon inside of his cell at the Coxsackie Correctional Facility, but his official cause of death has not yet been released.

Martinez-Estrella was convicted of second-degree murder, second-degree conspiracy, and second-degree gang assault. He was resentenced for the murder charge in May and was serving 25 years to life with the possibility of parole.

The new sentencing came after the New York State Supreme Court tossed the first-degree murder conviction and wrote that prosecutors did not prove an essential element of the crime - that the defendant inflicted torture on Junior.

News 12 Feature: Justice for Junior

On the night of June 20, 2018, Lesandro 'Junior' Guzman-Feliz was fatally attacked outside a Bronx bodega. The 15-year-old was chased down the street, dragged out of the Belmont bodega where he sought refuge, and stabbed and slashed multiple times by his attackers, one of which used a machete. The entire attack was caught on surveillance video.

"The gang doesn’t have any more choices, only one of two ways – jail or cemetery,” said Junior's mother Leandra Feliz. “[Martinez-Estrella] was fighting for his freedom, and now he’s going to have freedom in hell with the evil.”