The transfer keeps the 19-year-old in custody to serve the rest of a 40-year sentence.
ARLINGTON, TX — A Tarrant County judge has ordered Jonathon Porter, the gunman convicted in the 2023 Lamar High School shooting, transferred from juvenile custody to the adult prison system to continue serving a 40-year sentence.
The ruling marks the next major step in a case that began with gunfire outside the Arlington campus before classes on March 20, 2023. Porter was 15 at the time of the shooting and was handled in juvenile court. He is now 19, which required the court to decide whether he should be released under supervision or moved to the Texas Department of Criminal Justice.
Porter was sentenced in September 2023 after admitting he fired a shotgun into a group of students waiting near the doors at Lamar High School. The shooting killed 16-year-old Ja’Shawn Poirier and injured another student, later identified as I’yahni Reynolds, who was struck in the face by shrapnel while sitting on a bench. A Tarrant County jury gave Porter the maximum sentence available in juvenile court for capital murder and attempted capital murder. At the time, Judge Alex Kim told Porter that his conduct while in state juvenile custody would matter when the court later decided whether he should enter the adult prison system.
That question returned to court after Porter turned 19. Prosecutors argued that his record in juvenile custody showed he remained a danger and had not shown enough progress in treatment programs. Prosecutor Lloyd Whelchel said Porter had been involved in two fights in the six months before the hearing, including one the month before the transfer decision. Whelchel also pointed to the original shooting, saying Porter killed Poirier, injured Reynolds and endangered about 20 other students outside the school that morning. Prosecutors also cited an attempted escape that happened on the day Porter’s trial had been set to begin.
The escape attempt was captured on video and became a key part of the transfer hearing. Court testimony in earlier proceedings showed Porter asked a juvenile detention officer for a roll of toilet paper about 2 a.m., then struck the officer, took keys and later took a flashlight while leading officers through the detention center. Prosecutors said the incident showed Porter could not safely be released. Defense attorney Lisa Herrick argued that Porter could be supervised on parole and that his needs could be handled in the community under rules, restrictions and oversight. Kim rejected that request after hearing witness testimony.
The case drew attention from the start because Porter was not tried as an adult, even though prosecutors had sought that route. The judge kept the case in juvenile court, where the law capped the punishment at 40 years. After the jury issued that sentence, Porter was sent to the Texas Juvenile Justice Department. The court process left open the later decision now made by Kim: whether Porter would be paroled under supervision or transferred to adult prison before serving the rest of his sentence.
The shotgun used in the shooting also led to a separate federal case against Porter’s father, John Edward Porter. Federal prosecutors said agents searched his apartment after the Lamar High School shooting and found paperwork for a Mossberg model 500 12-gauge shotgun, the same kind of weapon recovered from the scene. They also found other firearms. John Edward Porter, who had prior felony convictions in Louisiana, pleaded guilty to being a felon in possession of a firearm and was sentenced in September 2023 to 77 months in federal prison.
Family members and survivors were present as the court considered Porter’s future. Poirier’s mother, Rashone Jacob, said after the ruling that the judge made the right decision. She said her son was killed for no reason and that Porter knew he should not have taken a gun to school. Reynolds also attended the hearing and described the lasting trauma from being hit in the face by shrapnel. “If I had moved my head or body in any other way, it could’ve lodged in my neck,” Reynolds said.
Kim addressed Porter directly before ordering the transfer, saying the court had to weigh the risk of further violence. “What bothers me is releasing somebody that may go back and engage in the same conduct again, and you haven’t shown me that you won’t,” Kim said. Porter will now serve the remainder of his 40-year sentence in the adult correctional system, closing the juvenile custody phase of a case that has stayed with Lamar High School families since the morning of the shooting.
Author note: Last updated June 22, 2026.