Armstrong is now a 22-year-old father himself.
Investigators said Armstrong killed his parents because they came down hard on him over slipping grades and smoking weed.
SEE RELATED STORY: Son charged in murder of parents goes before judge in pre-trial hearing
But in his 2019 trial, which ended in a mistrial, the defense claimed AJ's older half-brother, Josh Armstrong, could be the real killer, saying he was mentally unstable.
Our Courtney Fischer has been following the case since the beginning, and she spoke with AJ's attorney about the case which has remained in judicial limbo due to backlogs.
WATCH: AJ Armstrong talks about life as an accused killer
AJ Armstrong talks about life as an accused killer
"So, in this case are you happy it's gone on? Happy we've had COVID, and it's been pushed back so many times?" Courtney asked.
"Happy is not a word I'd use to describe it because you have to understand this is an enormous case with a lot of issues, under a lot of scrutiny, so every time we have a trial date, we have to prepare," said Rick DeToto.
Attorneys expect jury selection alone to take at least three days. If found guilty, AJ could spend life in prison.
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