FOX 26 Reporter Damali Keith has more as the re-trial of AJ Armstrong continued on Friday.

HOUSTON - Prosecutors in the A.J. Armstrong capital murder trial showed jurors his cell phone activity for the morning his parents were murdered. The now 22-year-old is on trial, accused of killing his parents when he was just 16. 

An investigator was on the witness stand Friday testifying about the timeline of events from Antonio Armstrong Junior’s cell phone, which prosecutors say helps prove their case. They say Armstrong murdered his parents as they slept.

AJ Armstrong Re-Trial: Officers testify about what they saw at Armstrong House

A Harris County District Attorney’s Office Digital Forensics Investigator Nathan Gates says that July morning in 2016 when former NFL player Antonio Armstrong Sr. and his wife Dawn were murdered in their home their 16-year-old son Antonio Armstrong Jr. was nearly non-stop on his phone. 

Gates says at 1:02 a.m. activity stops and the phone locks. At 1:04 a.m., the phone is plugged in. At 1:08 a.m., it’s unplugged and from 1:16 a.m. to 1:24 a.m., he says the phone display repeatedly goes on and off, prosecutors say as if someone used the phone for light in a dark area.

The gun used to kill the Armstrongs was found on the kitchen counter with a note that read, "I have been watching for some time."

At 1:40 a.m., Antonio Jr. called 911 saying from his third floor bedroom he heard gunshots in his parents second floor room. Defense attorneys are pointing to AJ’s older brother Josh, who suffers severe mental illness, as the possible murderer. 

AJ Armstrong Re-Trial: Officers describe Armstrong's demeanor after murdering parents

Josh Armstrong’s girlfriend gave tearful testimony and prosecutors read medical records saying Josh's mental health decline started after his parents were murdered. 

Prosecuting attorneys also told jurors two days before his parents were murdered, AJ searched, "How can a car be rigged to explode when started?"

Antonio Jr’s 911 call was played in court. Prosecutors point out AJ repeatedly asks if he can get his sister from her second floor bedroom, but never asks to check on his parents. Jurors also saw text messages between Antonio Jr. and his parents, and they tell him they're taking him out of private school and his car because of his lying, drinking, smoking marijuana, and failing grades. 

At one point AJ's mom says "I’m beyond disappointed...Every time you speak you lie…What did we ever do to you to deserve all the lies and schemes?"

MORE CRIME AND PUBLIC SAFETY

A veteran Houston police detective that responded to the double murder testified Friday that he never covered a homicide before or since where there are locked doors and windows and the murder weapon is still inside the home. He says a murder weapon is usually only left at a scene if it’s dropped in a struggle for instance. 

AJ says on the 911 call, "I hear a loud high-pitched noise." The HPD investigator told jurors that type of ringing in your ears often happens after someone fires a gun.

The trial is set to resume Monday morning.

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