By Dolores Chang and Joe Hutchinson For Dailymail.Com

Published: 12:31 EST, 8 March 2024 | Updated: 13:05 EST, 8 March 2024

The father of Michigan school shooter Ethan Crumbley made threatening statements from jail, his involuntary manslaughter trial heard on the first day of the court's proceedings. 

James Crumbley, 47, is charged with four counts of involuntary manslaughter, one for each teenager killed by his son at Oxford High School in 2021.

He was caught making threatening statements on a jailhouse telephone and in electronic messages, the Oakland County Sheriff's Office said late Thursday. Details about the specific threats James allegedly made and who he was allegedly targeting were not disclosed by authorities.

'His access to a phone or electronic messaging is now limited to communication with his lawyer,' according to the sheriff's office. 

Ethan Crumbley, then 15 years old, opened fire at the school in Oxford, Michigan, and murdered Hana St. Juliana, Madisyn Baldwin, Tate Myre and Justin Shilling. 

His father, James, is accused of failing to safely store a gun and ammunition at home and ignoring the mental health needs of Ethan. 

James Crumbley, the father of Michigan school shooter Ethan Crumbley made threatening statements from jail, his involuntary manslaughter trial heard on the first day of the court's proceedings

James, 47, is charged with four counts of involuntary manslaughter, one for each teenager killed by his son at Oxford High School in 2021 

He was caught making threatening statements on a jailhouse telephone and in electronic messages, the Oakland County Sheriff's Office said late Thursday

The bombshell claim about James making threats emerged during his trial late Thursday, with his lawyer promptly objecting to its public disclosure.

Judge Cheryl Matthews signed an order to revoke James's communications privileges, except for his ability to talk to lawyer and research information to help his defense. 

The judge did not attribute the order to the alleged threats and urged James's attorney and the prosecutor's office not to divulge further details to prevent media attention. 

The jury was sent home early on Thursday before the information about James's threats and restrictions were raised. 

DailyMail.com previously reported that James was seen sobbing and wiping away tears as the Thursday's trial heard details about the shooting. 

In court, Assistant Prosecuting Attorney Marc Keast said that James had been in the best position to stop the 'preventable and foreseeable' shooting. 

Keast said: 'What happened inside that school was truly a nightmare come to life. But it didn't have to be. That nightmare was preventable and it was foreseeable.'

Keast added: 'You're going to learn that those kids would still be alive today if James Crumbley seized any one of the tragically small and easy opportunities given to him to prevent his son from committing murder.'

DailyMail.com previously reported that James was seen sobbing and wiping away tears as the Thursday's trial heard details about the shooting 

James reacts to the testimony of then Oakland County Sherriff's Office Detective Edward Wagrowski on the first day of his trial

Assistant Prosecuting Attorney Marc Keast said that James had been in the best position to prevent the shooting

According to CBS, defense attorney Mariell Lehman said that the prosecution would try to prove that James knew what was going on with his son, but claimed that was false. 

She said: 'Ladies and gentlemen, James Crumbley was not aware that his son had access to that firearm.

'Please do follow the law. And I am confident; we are confident that if you do that if you follow the law, that you will find James Crumbley not guilty.'

In their opening statements, the prosecution spoke to the court for 23 minutes, while defense took just six minutes to lay down their arguments according to one reporter.

Before jurors entered court, Judge Cheryl Matthews made rulings that could benefit James. 

She said prosecutors can't use text messages between son and mother, months before the shooting, that suggested he was having hallucinations about demons. 

The first witness was Molly Darnell, a faculty member who was shot by a bullet that pierced her office door. 

Darnell, one of seven people wounded that day, stood, removed a jacket and showed jurors the spot on her upper left arm.

Darnell said that while she hid behind a cabinet, she texted her husband without telling him she had been shot, 'I love you,' she wrote. 'Active shooter.'

James, accompanied by Ethan, bought a Sig Sauer 9 mm handgun over Thanksgiving weekend in 2021. 

James Crumbley, 47, is charged with four counts of involuntary manslaughter, one for each teenager killed by his son at Oxford High School in 2021

Defense attorney Mariell Lehman said that the prosecution would try to prove that James knew what was going on with his son, but claimed that was false

Ethan Crumbley pleaded guilty to his crimes and is currently serving life in prison without the possibility of parole, after murdering four classmates in the Oxford High School shooting in 2021

On Thursday, the prosecution presented a picture showing James, left, with his son Ethan at a shooting range

Justin Shilling, 17, (left) and Tate Myre, 16, (right) were two of four students killed in the senseless shooting at Oxford High School in Michigan

Madisyn Baldwin, 17, (left) and Hana St Juliana, 14, (right) died in the 2021 shooting rampage at Oxford High School in suburban Detroit 

The boy called it his 'new beauty' on social media. His mother described the gun as a Christmas gift and took him to a shooting range.

Four days after the purchase, the parents went to Oxford High to discuss a violent image their son had drawn on a math assignment.

Alongside the drawing including phrases that said: 'The thoughts won´t stop. Help me.' There was a gun on the paper that looked similar to the Sig Sauer.

The Crumbleys didn't take Ethan home, and school staff - believing he might be suicidal - also didn't demand it. But no one checked the boy´s backpack for a gun, and the shooting happened that afternoon.

Defense lawyers insist the parents could not have foreseen the shooting and didn't commit a crime.

Jennifer Crumbley was found guilty on February 6 of involuntary manslaughter, making her the first parent in the US to be held responsible for a child carrying out a mass school attack.

Prosecutors said that Jennifer was more interested in pursuing an extramarital affair with a local fireman that caring for her son.

Following the killings, she texted her lover Brian Meloche that the shooting 'could have been prevented' and that the school should not have allowed him to return to class.

Jennifer Crumbley is taken into custody after a guilty verdict was read on Tuesday, Feb. 6, 2024

On the morning of November 30, 2021, school staff members were concerned about a violent drawing of a gun, bullet, and wounded man, accompanied by desperate phrases, on Ethan's math assignment. 

His parents were called to the school for a meeting, but they didn't take the boy home.

A few hours later, Ethan pulled a handgun from his backpack and shot 10 students and a teacher. No one had checked the backpack.

The gun was the Sig Sauer 9mm his father had purchased with him just four days earlier. His mother had taken her son to a shooting range that same weekend.

Following the shooting, a search of the teen's home found his room messy, with with paper targets from a shooting range on his wall. 

An empty bottle of whiskey was on a table beside his bed. At the time of the attack he was six years under America's legal drinking age. 

The safe used to house his Sig Sauer handgun was empty on his parents' bed. 

The gun used in the shooting was a Sig Sauer 9mm his father had purchased with him just four days earlier, seen here

Ethan's parents, James and Jennifer, were both charged in connection with the shooting

There were two other guns in a separate safe that could be unlocked with the code 0-0-0. 

During Jennifer's trial, the court heard that she was more interested in an extramarital affair, her horses and going for nights out on the town, than spending time with her son.

Jennifer's secret lover, local fire captain Brian Meloche, claimed she wanted to meet up the morning of the shooting, and said they had been meeting regularly in a parking lot across from her work. 

Jennifer told her lover that she had 'failed miserably' as a parent after her son was arrested for the murders. 

Her son Ethan addressed a packed court room after he was sentenced to life in prison. 

He said: 'What I did. My actions were because of what I chose to do. I could not stop myself, I do not diminish any ability to anyone that could have stopped me.

'They did not know and I did not tell them what I planned to do so they are not at fault for what I done. 

'I am a really bad person. I've done terrible things no one should ever do, I have lied. I've hurt many people, that's what I have done. 

'Whatever sentence it is I do plan to be better. I will change, it may not show it now but I am trying. 

Chilling diary entries written by Ethan include drawings of a gun being held to the head of a girl 

Jurors at Jennifer's involuntary manslaughter trial were shown disturbing drawings by her mass shooter son

'All I want is for the people I hurt to just have a final sense of culpability that justice has been served in any capacity. 

'Any sentence they ask for I ask that you do impose it on me, I want them to be happy, to feel secure. I do not want them to worry another day. I am really sorry. I cannot give it a back.'

In a journal, the shooter wrote about his desire to watch students suffer and the likelihood that he would spend his life in prison. 

He made a video on the eve of the shooting, declaring what he would do the next day. 

Jennifer is set to be sentenced on April 9 and could face a sentence of up to 60 years in state prison.