HOUSTON — A judge declared a mistrial in the second capital murder trial of Antonio "AJ" Armstrong Jr. in the 2016 shooting deaths of his parents. Jurors got the case on Monday and deliberated for nearly 18 hours but couldn't agree on a unanimous verdict.
He was 16 when prosecutors said he shot and killed his parents, Antonio Armstrong Sr. and Dawn Armstrong, while they slept in their Bellaire home.
Armstrong Jr.'s first trial also ended in a mistrial in 2019 when jurors couldn't agree on a verdict.
Defense attorneys said this time eight jurors believed Armstrong was innocent and four thought he was guilty. In his first trial, it was the other way around with eight jurors believing he was guilty.
"It's been six years, it's been two trials, it's been 40-50 witnesses, it's been probably millions of dollars in expenses by the district attorney's office. It's time to let this young man go," Defense attorney Chris Collings said.
Harris County District Attorney Kim Ogg issued a brief statement but didn't say whether they will try Armstrong a third time.
"We followed the evidence and stood up for Antonio Armstrong Sr. and Dawn Armstrong, who were murdered in their bed,” Ogg said. “We appreciate the time, effort and diligence of jurors as they were presented all the evidence in this brutal attack.”
KHOU 11 spoke with a juror who didn't want to be identified. They said doubt created by the defense is what led to a hung jury.
“It just got to the point where I couldn’t even talk anymore," the juror said. "Everyone kind of hand their mind made up, but it was very frustrating to hear everyone say, and I mean everyone, say, 'We know he’s not innocent but we still have doubt.'”
The prosecution's case
“This case is a parent’s worst nightmare, to come to the realization that the person you brought into this world would end your life,” prosecutor Ryan Trask said during closing arguments Monday.
Prosecutors said alarm records and other evidence proves that whoever killed the Armstrongs came from inside the house. They were killed with Armstrong Sr.'s gun.
“If officers arrive at that scene with the doors locked, the garage down, the windows closed, the murder weapon still in the home and they don’t assume it’s this defendant, they should take their badges away,” prosecutor John Jordan said.
RELATED: Day 1 | Opening statements begin in second murder trial for man accused of killing parents as teen
Prosecutors also said Armstrong Jr. "test-fired" the same gun into a pillow and tried to light a fire inside the home shortly before the shootings.
“He’s clearly experimenting with ways to kill his parents,” prosecutor Ryan Trask said.
After the killings, a prosecutor said Armstrong Jr. gave inconsistent statements to police.
The defense
The defense pushed back.
“Where in the world did this evidence go? Is Armstrong Jr. -- at the age of 16 -- some professionally trained assassin who somehow knows how to put all of this together to get away scot-free because there’s no evidence that points to him? I don’t think so," defense attorney Chris Collings said.
Armstrong's lawyers said there's no blood, DNA, fingerprints or gunshot residue linking Armstrong Jr. to the shootings.
“Where are the wet towels, the wet sinks, the wet showers, anything that would show that somebody cleaned themselves off or tried to hide evidence? It’s not there,” Collings said.
They also accused police of failing to consider other possible suspects.
“Within 11 minutes of going into that house before any evidence was processed, before they knew anything about the crime scene as far as forensics, before anything, they made up their mind he did it," defense attorney Rick Detoto said.
Armstrong Jr.'s defense also cast suspicion on his older brother, who lived nearby, had access codes to the home and suffered from mental illness.
The victims
Armstrong Sr. played football for Texas A&M and the Miami Dolphins and coached both of his sons when they were younger.
He was an associate pastor, according to police. Dawn Armstrong's Facebook page said they "serve in ministry together."
The couple owned 1st Class Training in Bellaire and Armstrong Sr. was also a motivational speaker.
Other family members have continued to support AJ Armstrong throughout both of his trials and many were in the courtroom Wednesday when the mistrial was announced.
WATCH: 2019 trial begins