ATHENS, Ala. (AP) — An Alabama youth accused of killing his father, stepmother and three young siblings when he was 14 went on trial Tuesday on capital murder charges.

Prosecutors accuse Mason Sisk of shooting his family to death in their north Alabama home in 2019, saying he told investigators he killed them because he was “fed up” with them. In their opening statements, prosecutors said Sisk told a teacher he wouldn’t be in school the following week and then took a handgun from the home of a family friend to shoot his family, news outlets reported.

The defense, which lost a challenge to prevent jurors from hearing about Sisk’s statements to police, argued that the boy didn’t have a plan to kill or any firearms experience.

Sisk, now 17, was charged as an adult with multiple counts of capital murder, but he can’t be sentenced to death if convicted because of his age at the time of the slayings.

John Wayne Sisk, 38, and Mary Sisk, 35, were found dead in their home in Elkmont on Sept. 2, 2019, along with their three children — 6-year-old Kane, 4-year-old Aurora and 6-month-old Colson. All had been killed with gunshots to the head, authorities said.

Authorities said Mason Sisk initially told police he was in the basement playing video games when he heard gunshots and ran outside to see a vehicle pulling away, but he later told investigators he’d killed the five.

A recording played during a pretrial hearing showed the youth told investigators about a possible motive for the killings.

“Yeah, they argue a lot, and I got fed up with it,” Sisk said in the recording. “And the kids were going through a lot.”

The defense has claimed Sisk only repeated to detectives what they had told him.

Prosecutors argued that Sisk had anger control issues and had threatened the entire family. In court documents filed earlier this year, prosecutors alleged Sisk previously put peanut butter in his stepmother’s coffee in an attempt to poison the woman, who had severe peanut allergies.

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