AJ Armstrong retrial: 2nd mistrial ruled in capital murder trial for Houston man accused of killing parents in 2016

HOUSTON – A judge ruled a second mistrial Wednesday after a jury was unable to reach a unanimous verdict in the capital murder case against Antonio “A.J.” Armstrong Jr., who was accused of killing his own parents.

The brutal slayings left a community and family divided on whether the young man was capable of committing the crime.

This was the second time A.J. faced trial in the death of his parents. A first mistrial was declared in 2019 because, after three days of deliberation, the jury back then could not reach a unanimous decision. Eight jurors believed A.J. was guilty, but four jurors voted not guilty.

Prosecutors said A.J. fatally shot his mother, Dawn, and father, former NFL player Antonio Armstrong Sr., as the couple slept at their southwest Houston home in the 5300 block of Palmetto Street on July 28, 2016.

A.J. said there was a masked person in the house, according to audio of the 911 call he made to police. Prosecutors said his claims were all a lie.

Prosecutors intended to show that A.J. was embroiled in conflict with his parents over failing grades and poor behavior. They said that the murders were committed by someone who was already inside the home, claiming that neither the burglar alarm system nor any other evidence showed signs of forced entry.

The second trial was a back-and-forth of presenting new evidence and an alternative suspect, A.J.’s older brother Joshua, who defense attorneys said could be the actual killer. Joshua was said to be the “black sheep” of the family and 19 years old at the time. He was also not Antonio Armstrong Sr.’s biological son.

A.J.’s defense team alleges Houston police hastily zeroed in on him before conducting a thorough investigation of the murder scene.

“We followed the evidence and stood up for Antonio Armstrong Sr. and Dawn Armstrong, who were murdered in their bed,” Harris County District Attorney Kim Ogg said. “We appreciate the time, effort, and diligence of jurors as they were presented all the evidence in this brutal attack.”

It is unclear if a third trial will take place.

Key highlights of trial, from various testimonies and cross-examinations.

First witness, an HPD lieutenant, takes the stand

A.J. became emotional and began crying when prosecutors described the details of his parent’s murder.

After the 2019 mistrial, the lead attorney, along with other attorneys filed several motions in the case, including asking a judge to allow them to introduce new evidence pointing to Joshua as the suspect.

“In 2,264 days, law enforcement has done almost nothing to investigate Josh,” said A.J.’s defense attorneys during opening statements. “We believe that the evidence will show you that that’s confirmation bias.”

Prosecutors told jurors that throughout the weeks-long trial they would hear evidence that supports the home being locked with alarms and motion sensors activated. They said the only other people inside the home were A.J. and his sister, and that their brother Joshua was not at the home.

“One of the things I anticipate that the defense will show you is medical records where Joshua Armstrong reported that he had witnessed the death of his parents. And I will anticipate they will ask you to make the leap that that means he was in the room when he killed his parents,” the state said. “And I want you to know now that Joshua did witness the death of his parents. He was at the scene when they were carted out and loaded up on stretchers and loaded up in the back of ambulances.”

A.J.’s defense attorneys said police missed an opportunity to focus on Joshua and his whereabouts the night of the murder. The defense also told the jury that they would hear some of Joshua’s medical records, which is information the jurors in the initial trial did not have. Joshua reportedly suffers from mental illness; however, prosecutors said his mental state deteriorated after his parents were killed, and not before.

The defense said, in contrast, A.J. had a great relationship with his parents and showed pictures to jurors to try and display that.

In addition to opening statements, the first witness, a lieutenant with Houston police took to the stand. The officer testified he was among the first to arrive and did not notice signs of forced entry. He said his officers cleared the three-story house and only found A.J. and his younger sister in the home. The also noticed a pistol on the kitchen counter beside a note. The lieutenant said, though he didn’t have physical evidence, he didn’t have reason to believe the shooter wasn’t inside the home.

First responders recount details

Jurors heard the testimonies of four witnesses during the second day of the re-trial.

All of the witnesses were first responders; three law enforcement officers and an EMT, who recounted what they saw when they arrived at The Armstrong’s home the night of the tragedy.

Tuesday started with the continuation of the prior day’s testimony involving a Houston police lieutenant. The law enforcement officer was one of the first to arrive at the townhome in southwest Houston. He testified he had officers separate A.J. and his sister, Kayra, because he believed the murderer was inside the house and not an intruder.

The lieutenant said the doors and windows to the home didn’t appear breached and that a pistol and a note were on the kitchen counter.

The second witness works as an EMT for the Houston Fire Department and described a bloody scene in the couple’s bedroom. The EMT testified he was the one who pronounced Dawn deceased and called for additional help for Antonio Sr., who he said was bleeding from the face but still had a pulse.

A Houston police sergeant was the third to take the stand. He testified that he was the one that opened a back door to allow other officers entry into the kitchen. The sergeant testified that a female officer had picked up a pistol that was left on the kitchen counter with her bare hands. He said he informed her to put the gun back and to document that as supplemental data for the police report, but she never did.

The veteran sergeant said he also informed the homicide detective.

A former homicide detective with HPD was the fourth witness to take the stand. He testified about his role in the investigation, which included interviewing A.J. after he was charged with the double murders.

Investigators describe suspect as ‘calm’ after parents were found dead

During day three of the trial, jurors heard from three additional witnesses.

The first witness was a Houston police officer who was one of the first people on the scene of the Armstrong’s home. The officer says he drove A.J. downtown to see a magistrate judge and then to the Houston Police Department for questioning. The officer testified that A.J. seemed calm, introverted, and eerie following the murders of his parents.

Jurors then heard from a retired Harris County hearing officer who testified that she read A.J. his rights and had him read the rights himself, give his interpretation, and then initial each line.

Jurors got to hear that audio in court Thursday.

Lastly, the seventh witness in the trial took the stand. That crime scene officer with the Houston Police Department testified his job was to document the scene and collect and preserve the evidence. The state then brought out several pieces of evidence, including the gun and note found on the kitchen counter that witnesses verified.

That witness also read the note, believed to have been written by the true killer, out loud to the court. It read, “I have been watching for some time.”

Baby sister testifies about big brothers

On Oct. 21, Kayra Armstrong was on the witness stand for about 90 minutes. During testimony, she spoke about the relationship that she had with both A.J. and Josh. Kayra said while there was a little bit of tension, her feelings about Josh were conflicted and even though she loves him, she felt somewhat unsafe around him at the time.

Kayra said that she was aware of the problems that both A.J. and Josh were having in the time leading up to the murder, and also admitted to knowing the financial woes of the family.

She also testified that the family only really used the garage door to enter house, and the alarm system was faulty. Kayra said the garage had a code, providing access to the home, and only family and close friend knew the number.

Kayra further testified that, on the night of the murders, she recalled being picked up and driven home by A.J. and he seemed normal. She said she was later awakened by A.J. when police were at the door.

Regarding her brother Joshua, Kayra spoke about incidents of Josh trying to burn down their grandmother’s home once and, just days before her mother and father were killed, Josh allegedly set a small fire inside their family’s home.

During cross-examination, Kayra acknowledged that she spent the week preceding the murder at her grandmother’s place, so she would not have any direct knowledge of how the family dynamic was with her parents and her brothers.

Kayra also admitted that A.J. was constantly in trouble with their parents, though she said it wasn’t an “alarming” thing.

Prosecutors brought up the fact that A.J. was “being mean to her around this period.”

Testimony of digital forensics investigator

Prosecutors interviewed a digital forensics investigator with the Harris County District Attorney’s Office. Evidence was presented showing, on the night of the murder, A.J. sent himself text messages pretending to threaten “Blake,” reportedly someone who spoke ill of his girlfriend.

During cross examination, the defense said that, even if A.J. did make up the threat to Blake, it shows that he was just trying to diffuse the situation with Blake rather than resorting to violence. They also said the teen was sending heartfelt messages to his girlfriend at the time.

The defense further argued that those messages would’ve been sent at 10:19 p.m., so it speaks to A.J.’s state of mind that night.

Defense attorneys did get the investigator to admit that, out of the thousands of texts he went through from A.J., none of them showed disrespect to his parents.

Prosecutors came back to argue that text messages did appear to show that Dawn, the mother, did think differently of A.J. shortly before her death. Messages showed the mother scolding him, saying he was lying about different things and sneaking out of the house.

Questions surrounding alarm system

Attorneys from both sides disagree on the validity of the security system, which logged activities from the night of the murder.

Prosecutors said motion sensors from within the home, and the activation and de-activation of the alarm system, shows the timeline of events, which they said proves that the murderer was someone already inside.

July 28, 2016:

  • 9:52 p.m.: Parents set alarm
  • 10:39 p.m.: Motion sensors on second floor go idle due to no movement
  • 1:09 a.m.: Upstairs sensor activated as motion detected (floor of parents’ bedroom)
  • 1:25 a.m.: Downstairs sensor activated
  • 1:56 a.m.: System disarmed by key fob
  • 1:57 a.m.: Front door/garage open
  • 1:59 a.m.: Front door/ garage closed

The defense said anything about the alarm monitoring system was “garbage” because it had dozens of errors. ADT records from the three and a half weeks prior to the murders were presented, showing the alarm motion sensors logged incorrect information 77 times.

Records show A.J. was using his cellphone, communicating with his girlfriend, up until 1:02 a.m. He called 911 at 1:40 a.m. reporting hearing gunshots in his mother and father’s room. Prosecutors said, during that 38-minute window, he was murdering his parents.

The defense said that is not a possibility, claiming there was no gunshot residue, no blood, no fingerprints and no DNA connecting the teen to the heinous crime. They said Joshua had mental health issues and motive.


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About the Authors:

Mother of two. Award-winning lover of digital storytelling, sparked by my fascination of being a fashionable gossip like my favorite "Willona Woods" character from "Good Times." On the serious side, president of the Houston Association of Black Journalists and dedicated community servant. Happy to share the news with you each and every day!

Moriah Ballard joined the KPRC 2 digital team in the fall of 2021. Prior to becoming a digital content producer in Southeast Texas and a Houstonian, Moriah was an award-winning radio host in her hometown of Lorain, Ohio and previously worked as a producer/content creator in Cleveland. Her faith, family, and community are her top passions.