HOUSTON — The fourth day of the capital murder retrial against A.J. Armstrong focused on the alarm system at the family's home the night his parent -- Dawn Armstrong and Antonio Armstrong Sr. -- were shot and killed in their beds back in 2016.
Thursday was the fourth day of testimony in the case. A.J. Armstrong is standing trial for capital murder for the third time in the case of his parents' killings.
Prosecutors said Thursday that Armstrong has to be the killer because the alarm system showed no signs of an intruder that night, but the defense tried to point out potential flaws in the system that would have allowed someone to get inside undetected.
Testimony resumes Friday.
Trial updates
Day 2 - Aug. 1: Jurors in AJ Armstrong Jr. trial hear from HPD officers who responded to the 2016 murder scene
Day 1 - July 31: Prosecutors, defense in AJ Armstrong's third capital murder trial spar over blood spatter bombshell in opening statements
Background
Below is the background of the case and reports from the first two mistrials.
2016 killings
On July 29, 2016, investigators said they believe Armstrong Jr. shot his parents at close range while they slept inside the Bellaire-area home.
According to authorities, Dawn Armstrong was shot twice in her head and Antonio Armstrong Sr. was shot once. They said both had pillows over their heads. Dawn was pronounced dead at the scene while Armstrong Sr. was taken to a hospital where he later died. Both were 42.
Houston Police Sgt. J.P. Horelica said after discovering there was no forced entry and a bullet hole in the ceiling of the Armstrongs' bedroom, the focus shifted to Armstrong Jr. as a suspect. Brewer said a .22-caliber pistol was found on the kitchen counter along with a note. Also, Brewer said an upstairs motion detector caught movement at 1:09 a.m. Brewer said police found three shell casings in the master bedroom.
“The alarm tells us more than just the killer came from inside the house. The alarm tells us that the killer came from upstairs,” Brewer said when KHOU 11 News covered the story in 2019.
Armstrong Sr. was a motivational speaker. He and his wife owned 1st Class Training in Bellaire. Armstrong Sr. played football for Texas A&M and the Miami Dolphins and coached both of his sons when they were younger. Antonio Sr. was also an associate pastor, according to police. Dawn Armstrong's Facebook page said they "serve in ministry together."
First trial
Armstrong Jr.'s first murder trial began on April 2, 2019. He was tried as an adult and faced life in prison if found guilty. Due to Armstrong Jr.'s age at the time of the crime, a conviction would mean automatic life in prison with a minimum of 40 years to be eligible for parole.
During the first trial, Armstrong Jr. entered a not-guilty plea before opening statements. The initial trial ended in a mistrial on April 26, 2019, when jurors weren't able to reach a unanimous decision in the case.
Second trial
A judge declared a mistrial in the second capital murder trial of Armstrong Jr. in October 2022 after jurors deliberated for nearly 18 hours but couldn't agree on a unanimous verdict.
Defense attorneys said then that 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.