Judge will allow defense to introduce evidence of alternate perpetrator in Antonio ‘AJ’ Armstrong murder trial

Defense attorneys in the case of a man charged with killing his parents will be allowed to introduce evidence that an “alternate perpetrator” pulled the trigger.

Antonio “AJ” Armstrong appeared before a judge Friday for a pre-trial hearing, ahead of his double capital murder trial, which is scheduled for Jan. 2022. Armstrong is accused of killing his parents as they slept in July 2016. He was 16 years old at the time.

However, jurors in 2019 couldn’t come to a unanimous agreement on Armstrong. The first trial ended with a hung jury.

Friday’s pre-trial hearing involved multiple motions for Judge Kelli Johnson to consider. The big one was the defense’s push for the allowance of an alternate perpetrator theory. In sum, that allows the defense to introduce evidence during the re-trial that bolsters their claim that AJ is innocent. Judge Johnson ruled in the defense’s favor on the motion.

“We think it was a successful day,” said Rick DeToto, Armstrong’s lead defense attorney.

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“By the court ruling the way she did, it goes a long way in helping us to make that argument to a potential jury,” DeToto continued.

The ruling will allow them to introduce their claims during opening arguments in January.

“We will be able to present evidence hopefully early on, explain to the jury in opening arguments of what we believe our alternative theories are,” said Chris Collings, another of Armstrong’s attorneys.

The defense plans to argue the alternate perpetrator is Joshua Armstrong, AJ’s older brother, who lived near his parents’ home in southwest Houston.

RELATED: Documents: Antonio Armstrong Jr.’s brother says he witnessed slaying of parents

During the first trial, Kayra Armstrong, the youngest sibling, testified Joshua had lived with them but moved out not too long before the murders. Testifying for the defense, she said Josh and his parents didn’t have the best relationship.

However, what’s expected to be different during the retrial is evidence the defense argues implicates Joshua Armstrong. During Friday’s pre-trial hearing, AJ Armstrong’s legal team cited Joshua’s medical records from his documented struggle with mental illness.

One record allegedly cites Joshua as saying he saw his parents be murdered.

Prosecutors fought hard to sway judge Kelli Johnson in their favor. They argued introducing Joshua would confuse jurors, while also placing a man who hasn’t been charged on trial.

RELATED: AJ Armstrong trial: What we know about teen accused of killing parents

While Judge Johnson sided with the defense, prosecutors have another axe to grind in what they argued was the defense attempting to negatively affect the case by speaking on record with the media.

“[DeToto] has run afoul of Texas Disciplinary Rules of Professional Conduct regarding trial publicity,” the motion claims.

A hearing for that motion has been set for Sept. 22.