Brandon Lee is facing murder charges for the deaths of his mom Christa Lee, 58, and his girlfriend, Krystal Hylton, 28.
On Monday, the court heard from a psychiatrist who said Lee's traumatic upbringing and dependency on alcohol caused him to act impulsively.
At one time, he worked on Wall Street and even modeled for GQ Magazine.
But Dr. Moria Artigues said there was a downward spiral related to his addiction.
She said he was void of feelings and pointed to the confession tape, where he "matter-of-factly" described killing his mom and girlfriend.
"Brandon would become very verbal aggressive, belligerent," said Artigues. "He shut himself down emotionally at an early age. He was able to identify that saying that 'I just felt so hopeless about doing everything. I just decided not to have feelings about it.'"
Lee became agitated by testimony about his mental health and had an outburst in the courtroom.
"l'll be taking the stand," he said while standing to his feet.
The judge ordered him to sit down and remain quiet for the rest of the proceedings.
The trial saw chilling evidence Friday as prosecutors played video of Lee being interrogated and confessing to details of the December 2015 crime.
"It was like she gave up...It was like she wanted to die," Lee was heard on video saying about his mother.
Police arrested him and then recorded a 90-minute video interview in which he confessed. He gave only few details about how he strangled his girlfriend, but he was much more detailed in talking about killing his mother a week earlier the same way at the Cary apartment they shared.
On the first day of trial, prosecutors showed Lee's phone call to police and video interview with investigators. They say it showed he had a "cool state of mind," which is an element of first-degree murder.
His defense attorneys argue he did not plan to kill either of them.