Court docs reveal more on months leading up to double murder-suicide in Surprise

Details emerge on months before Surprise murder-suicide

SURPRISE, Ariz. - We're learning more about the months leading up to a double murder-suicide where a father in Surprise reportedly took his life, along with his children's.

FOX 10 obtained family court records revealing disturbing allegations made by Brock Mater's estranged wife.

A petition for an order of protection was filed against Mater by his estranged wife last fall. Documents say the father of her children had been abusive to her and threatened to kill himself.

Court records show she petitioned for an order of protection on October 11, 2023, alleging that her husband threatened to kill himself after she asked for a divorce.

The petition she filed also says that Mater owned guns, and she wanted the order to prohibit him from possessing firearms.

A week later, the divorce filing reveals that Mater took his seven-year-old and six-year-old out of school, taking them to a hotel without their mom knowing.

Then, he allegedly called the police, saying he was having suicidal and homicidal thoughts, fearing for himself and the kids. Mater was taken to a Peoria hospital and was kept on a psychiatric hold.

Brock Mater (Surprise PD)

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His response filing in family court says he was treated for bipolar disorder.

"Mr. Mater was undergoing mental health treatment. It is our understanding that while they were separated, he was going and actively seeking and actively receiving mental health treatment and that treatment was going well," said Surprise Police Sgt. Rick Hernandez.

The children's mother also says, according to court docs, that Mater was "speaking of demons and cults and was highly agitated and fearful."

Documents allege a mental break caused Mater to believe his church and wife were under "Satan's control."

A video posted on Mater's Facebook profile shows him receiving a spear as an award at his church on Father's Day 2023. The church says it has no comment.

Temporary orders after a November hearing say Mater was taking medication and both parents would share equal parenting time and legal decision-making.

Court records say Mater's wife asked for the order of protection to be dismissed on May 1 as the divorce was close to being final.

Records also show a psychological evaluation report was filed in late March.

A motion for an emergency status conference was filed in this family court case on Tuesday after the double murder-suicide.

The law firm representing the children's mother says it doesn't have a comment at this time. As for Mater's lawyer, we have not heard back.

If you or a loved one is feeling distressed, call or text the 988 Suicide & Crisis Line for free and confidential emotional support 24 hours a day, 7 days a week.

CLICK HERE for the warning signs and risk factors of suicide and CLICK HERE for more on the 988 Lifeline.