(NewsNation) — Testimony has ended for the week in the trial of the father of a Michigan school shooter.

Ven Johnson, the attorney who represents the families of some of the victims, joined “Elizabeth Vargas Reports” to discuss the proceedings in the trial of James Crumbley.

“I don’t think that this jury is going to buy any of the defenses in this case,” Johnson said.

Crumbley is charged with involuntary manslaughter in the shooting deaths of four students at Oxford High School in 2021 carried out by his son Ethan.

Prosecutors say his gross negligence was the cause of the tragedy.

Crumbley’s attorney said that his client did not know his son posed any danger or that he had access to the gun.

“The father … clearly knew (his son) was having severe difficulties, and what I believe to be obvious signs of a mental health crisis, and did nothing about it,” Johnson said. “Didn’t help him to get to a therapist or intervention at all. And then he buys him a semiautomatic handgun days before the shooting.”

Today, the prosecution called Robert Koteles to the stand. He was the crime scene supervisor for the sheriff’s office and was called to the school after the shooting that day.

Koteles testified the shooter fired into multiple classrooms, leaving behind a trail of carnage.

The jury also heard today from Cammy Back, the office manager at the gun shop where James bought the firearm for his son.

She testified that his son was with him in the store and that they were provided a safety pamphlet and gun lock for the firearm they purchased.

James Crumbley has been in jail since his arrest more than two years ago. The sheriff’s office said Friday that his use of a phone and tablet would be restricted after he used them to make “threatening statements” while in custody.

“The threatening comments,” Johnson said, “that’s very, very scary for everyone. Who are the people that were supposed to be the subject of his threats? Obviously, my clients appreciate the judge stepping up and not allowing that to occur because, certainly, that causes concern for everyone.”

James’ son Ethan was sentenced to life in prison without parole, and his wife Jennifer was convicted of the same charges he now faces just a month ago.

The Crumbleys are the first U.S. parents to be charged with having criminal responsibility for a school shooting committed by a child.

The Associated Press contributed to this report.