PONTIAC, Mich. (AP) — A judge restricted the use of a phone and tablet by the father of a Michigan school shooter after he used them to make “threatening statements” from jail, authorities said Friday.

James Crumbley is on trial for involuntary manslaughter in the deaths of four students killed by his son Ethan Crumbley at Oxford High School in 2021. He’s being held in the Oakland County jail.

The sheriff’s office, in a brief statement, didn’t elaborate on the threats.

The issue came up in court after the jury went home Thursday. Judge Cheryl Matthews said she would sign an order agreed to by Crumbley’s attorney and the prosecutor’s office.

But the judge made no mention of threats as the reason. She suggested the matter would be unflattering to Crumbley and urged both sides to simply agree to an order and avoid a public airing.

There could “be an article about it” in 10 minutes if details were made public, Matthews said.

Crumbley made “threatening statements” in jail “while on the phone and in electronic messages,” the sheriff’s office said.

He can use a phone or tablet only to communicate with his lawyer or clergy, the judge’s order states.

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A gag order in the case bars attorneys from speaking to reporters.

Trial testimony, meanwhile, will resume Friday.

James Crumbley isn’t accused of knowing beforehand that 15-year-old Ethan planned to shoot up Oxford High, but prosecutors allege that his gross negligence was a cause of the tragedy.

The father did not safely secure the gun at home and ignored his son’s mental distress, assistant prosecutor Marc Keast told the jury Thursday.

The shooter’s mother, Jennifer Crumbley, was found guilty of the same involuntary manslaughter charges last month.

Ethan, now 17, is serving a life prison sentence for murder and terrorism.