An ex-NFL star and wife were executed as they slept. Seven years and three trials on, their son is behind bars

Antonio Armstrong Jr has been convicted of the 2016 murders of his parents Dawn and Antonio Armstrong Sr – bringing some sort of conclusion to a chilling case that has rumbled on through three trials and seven years. Graig Graziosi reports

It was a crime that shocked the nation back in 2016.

Former NFL star Antonio Armstrong Sr and his wife Dawn Armstrong were executed in their beds, shot to death as they slept in the Houston home they shared with their 16 year-old son and 12-year-old daughter.

The killer left a chilling note behind at the scene warning: “I have been watching you for a long time. Come get me.”

Now, seven years and three trials on, their son – now 23 – is facing the prospect of a life behind bars after being convicted of their murders.

Yet, he continues to maintain his innocence and the family refuses to believe he played any part in the slayings.

The murders

It all began back on the night of 29 July, 2016, when a 911 operator near Houston received a call from a concerned teenager.

Sixteen-year-old Antonio “AJ” Armstrong Jr told the operator that he heard gunshots at his home.

When police arrived to check on the teenager, they found that both of his parents had been shot in the head while sleeping in their beds.

The only other people in the home at the time were AJ and his 12-year-old sister. AJ had had to disable an alarm to allow the officers into the home.

The boy's mother, Dawn Armstrong, was pronounced dead at the scene. His father, former NFL linebacker Antonio Armstrong Sr, was rushed to a hospital where he died from his wounds.

When police searched the house, they found the murder weapon — a .22 calibre pistol belonging to Mr Armstrong Sr — and a terrifying note.

Dawn and Antonio Armstrong Sr (Family )

"I have been watching you for a long time. Come get me," the note read.

But there was no shadowy killer waiting to play cat and mouse with the Houston police.

Instead — at least so far as a Texas grand jury is concerned — the teenager who made the call pulled the trigger, planted the gun, and wrote the threatening note on the night of his parents' deaths, according to the New York Post.

Seven-year legal battle

Hours after the murders, AJ was charged with murder but the case rumbled on through the courts for more than seven years.

AJ has stood trial for capital murder three times – with the first two ending in hung juries and mistrials being declared.

At his third time this week, the jury reached a unanimous verdict.

AJ, now 23, was found guilty on Wednesday and was sentenced to life in prison for the murder of his parents when he was 16 years old.

He stood quietly in the courtroom when his verdict and sentencing were read out. His wife — who was dating him at the time of the murders — sobbed.

Kate Ober, wife of Antonio Armstrong Jr, cries as she listens to the verdict (AP)

Jurors spent approximately 10-and-a-half hours deliberating before ultimately deciding Armstrong Jr was guilty. It was his third time at trial; the first two ended with hung juries, resulting in the need for retrials. Armstrong Jr has been wearing an ankle monitor since 2017 as a result.

Since the night of the murders in 2016, Armstrong Jr has married his high-school sweetheart, Katie, and became a father. Now he will spend the rest of his life interacting with them through prison glass.

During the trial, prosecutors revealed that a week before the murders, Armstrong Jr had used the murder weapon to shoot a pillow and a blanket inside his bedroom. The bullet lodged in his bedroom floor. They said he also lit a fire outside his parents' bedroom door two nights before he killed them.

The evidence against Armstrong Jr did not end there; prosecutors revealed the teenager had searched for instructions on building a car bomb using his iPad. Investigators also doubted a story he told them about a masked intruder entering his home on the night of the murders.

He reportedly told investigators that he saw a 6-foot-tall man in a mask flee his home on the night his parents were killed. However, he did not include that information in his initial reports, and data pulled from the home's security system showed no records of anyone entering the house on the night of the murders.

AJ Armstrong Jr sobs as he denies killing parents (ABC13)

Prosecutors argued that the teenager was lashing out after his parents scolded him for getting kicked out of his high school. The defence rejected that argument, and pointed to his mental health issues, which included paranoia and schizophrenia.

After killing his parents, Armstrong Jr was placed in psychiatric hospitals, where a doctor testified for the defence that the teenager believed he was both a god and a devil.

A family divided

His defence plans to appeal the verdict.

Despite the damning evidence and the verdict in court, several members of the Armstrong family continue to stand by the convicted killer.

AJ’s great uncle Harvey Armstrong told Fox26 that he was “crushed emotionally” and left “devastated and in disbelief” by the guilty verdict.

“I know AJ. I know in his heart he could not kill his father and mother,” he said.

Antonio Armstrong Sr used to play for the NFL (ABC13)

Harvey Armstrong, who also played eight seasons in the NFL, still hopes that one day AJ will follow in the family’s sporting footsteps.

“He said uncle, when I get out of this whole stuff, this mess, I want to go back and play football,” he said.

“God will find a way. I’m convinced of that. Faith over fear. I’m going to have faith that my nephew will be home soon.”