A.J. Armstrong is due to appear before a judge in Houston on Tuesday as his lawyers seek permission for a fourth trial over the 2016 murders of his parents.
The hearing will examine whether prosecutors failed to disclose information about a state expert before Armstrong’s third trial. It will not, by itself, overturn his conviction or guarantee a retrial.
A.J. Armstrong fourth-trial hearing
The Texas Court of Criminal Appeals last month rejected an attempt by the Harris County District Attorney’s Office to stop the proceedings, allowing the case to return to the 178th District Court.
The state’s highest criminal court lifted a stay that had kept the hearing on hold for almost a year. The ruling found that the lower court could consider whether Armstrong had grounds to seek a new trial. ([click2houston.com](https://www.click2houston.com/news/local/2026/09/17/texas-court-clears-way-for-hearing-in-aj-armstrong-murder-case/))
Armstrong’s defence team argues that prosecutors should have disclosed a complaint made to the Texas Forensic Science Commission about Celestina Rossi, a blood-spatter expert involved in the case.
The complaint related to an unrelated investigation and accused Rossi of fabricating or planting evidence. It was later dismissed, but Armstrong’s lawyers say they did not know about it until after his third trial and that the information could have affected their decisions in court. ([click2houston.com](https://www.click2houston.com/news/local/2026/09/17/texas-court-clears-way-for-hearing-in-aj-armstrong-murder-case/))
Rick DeToto, one of Armstrong’s lawyers, said the defence wanted prosecutors to explain what they knew about the complaint and when they knew it.
The Harris County District Attorney’s Office has defended the conviction. A spokesperson said the office was disappointed by the appeals court ruling and would continue to defend the jury’s verdict.
Armstrong was convicted of capital murder by a Harris County jury in August 2023 and sentenced to life in prison, with the possibility of parole after 40 years. He is now 26.
His first two trials ended without a verdict. Jurors deadlocked in 2019, while a second jury failed to reach a decision in 2022, leading to a mistrial. ([fox26houston.com](https://www.fox26houston.com/news/a-j-armstrong-case-texas-court-criminal-appeals-rules-regarding-move-possible-4th-trial.amp))
The 2016 Houston murders
Armstrong’s parents, Dawn Armstrong and Antonio Armstrong Sr, were shot in their bed at their home in the Bellaire area of Houston on 29 July 2016. Armstrong, who was 16 at the time, made the emergency call to police.
Prosecutors argued at trial that he killed his parents and attempted to conceal his involvement. Armstrong denied the allegations and said he had seen a masked intruder inside the house.
A key issue at the third trial was the discovery of two tiny blood traces on Armstrong’s T-shirt, beneath or close to a police identification sticker placed on the clothing after his arrest.
The defence argued that the material may have resulted from contamination. Armstrong has also filed a civil lawsuit against the City of Houston alleging that the blood evidence was planted or mishandled, claims that have not been proven in court.
The judge hearing Tuesday’s evidence will decide whether the undisclosed complaint and related testimony could have affected the outcome of Armstrong’s 2023 trial. Only if the court grants his motion would the case move towards a possible fourth trial.
