Although the gunman who killed their children and his parents who gave him the gun are behind bars, families of the Oxford High School shooting victims say their fight for justice is far from over. 

Victims' parents gathered for the first time without their attorneys alongside members of the Oxford Board of Education, the town's chief of police, the county prosecutors office and other supportive parties to demand a full investigation into the events that led up to Ethan Crumbley's Nov. 30, 2021 attack on the Michigan school that killed four students and injured seven others, including a teacher.

"This is not about identifying people to prosecute – that's what the attorney general continues to get wrong on this," one of the gathered group said at the Monday press conference. "While that is a part of the story, the bigger piece is to drive the chance to change the future... this is an opportunity to leverage the attack as a lesson learned."

The parents say that they are still in the dark about what could have been done differently leading up to that day and want accountability from the school district, officials and staff who they say have escaped liability over their roles in the tragedy. 

MICHIGAN SCHOOL SHOOTER ETHAN CRUMBLEY SENTENCED TO LIFE AFTER ADDRESSING COURT: 'I AM A REALLY BAD PERSON'

Ethan Crumbley in court

Ethan Crumbley answers "yes" to charges against him during his pre-trial hearing at Oakland County Courthouse on Oct. 24, 2022 in Pontiac, Michigan. (Clarence Tabb Jr./Detroit News via AP, File)

Although the Oxford Community Schools Board published a 590-page independent investigation carried out by Guidepost Solutions, the parents said only a third of involved parties cooperated. 

"In certain critical areas, individuals at every level of the district... failed to provide a safe and secure environment," the investigation concluded.

School counselor Sean Hopkins and former Dean of Students Nicholas Ejak –  "the two people with the most knowledge about the decision to allow the shooter to go back to class" – refused to cooperate with the investigation, Guidepost wrote.

Only 51 of 143 current or former Oxford Community Schools employees responded to the company for interviews. Guidepost asked the district to require employees to participate, but they did not do so.

"How do we know what we don't know," said Steve St. Juliana, whose 14-year-old daughter Hana St. Juliana died in the shooting, which also claimed the lives of Tate Myre, 16; Madisyn Baldwin, 17; and Justin Shilling, 17.

JENNIFER AND JAMES CRUMBLEY SENTENCED IN SON'S MICHIGAN SCHOOL SHOOTING

James and Jennifer Crumbley

James and Jennifer Crumbley, parents of Oxford High School shooter Ethan Crumbley, appear in court for a preliminary hearing. (AP Photo/Paul Sancya, File)

"What has the state done with [the Guidepost investigation]? They haven't even acknowledged it," another parent said. "There's a lot already out there that needs to be turned into something, be turned into a countermeasure and turned into change."

The group wants the state of Michigan to carry out and fund this investigation, and use subpoena power to force those who refused to talk before to do so now. 

The majority of the information the victims' parents have learned about the shooting came from the trials of James and Jennifer Crumbley, who became the first parents in the U.S. to be held criminally responsible for a mass school shooting carried out by their child. 

Both Crumbleys were convicted of involuntary manslaughter, concluding that they were responsible for the deaths of the Michigan students because, among other things, they did not properly store the gun that their son snuck out of their house that day.

Prosecutors argued at both trials that the parents ignored indications that their son was depressed and crying out for help.

They said that the Crumbleys could have prevented their son's actions if they had disclosed that their son had access to a gun during a meeting at school on the morning of the shooting and brought their son home after learning during that meeting of a troubled drawing he made on a math worksheet. The drawing depicted a bleeding body, a gun and the words, "The thoughts won't stop. Help me."

MICHIGAN SCHOOL SHOOTER'S MOM WANTS HOUSE ARREST, BACKTRACKS ON REGRETS AND KILLER'S PARENTS FACE SENTENCINGS

A vigil for the victims of the Oxford High School shooting

Four students were killed and seven others were injured on Nov. 30, 2021, when student Ethan Crumbley opened fire at Oxford High School. (Scott Olson)

Ethan Crumbley is serving a life sentence without the possibility of parole after pleading guilty to all charges. He and his parents are appealing their sentences. 

However, the victims' parents on Monday insisted that the school was the fourth culprit in the massacre. 

No government entity has weighed in on the Guidepost investigation or affirmed any of its findings; Michigan Attorney General Dana Nessel offered three times to review the school shooting, the Detroit Free Press reported, but the Oxford School Board rejected her offers. 

The Oakland County Prosecutor's Office, which had representatives at Monday's meeting, gave multiple school officials confidential immunity agreements, including Hopkins and Ejak, according to the Free Press. 

CLICK HERE TO GET THE FOX NEWS APP 

Madisyn Baldwin's mother

Nicole Beausoleil, the mother of Madisyn Baldwin, one of four Oxford High School students who was killed by Oxford High School shooter Ethan Crumbley, reacts to the jury's verdict of guilty on all four counts of involuntary manslaughter in the trial of Ethan Crumbley's father, James Crumbley on March 14, 2024 at Oakland County Circuit Court in Pontiac, Michigan. (Bill Pugliano/Getty Images)

"The state [has] basic immunity unless they’re the ones pulling the trigger themselves, they’re covered, they have a union," one speaker said on Monday. "Colorado changed their law after Columbine that in cases about school violence, that that immunity was not automatic. If you were grossly negligent, you could be held accountable."

"It’s quite clear, this is an epidemic that’s growing. It’s not a matter of if, it’s a matter of when this will happen again," another parent said. "Even if it can’t be prevented, if we can come up with countermeasures… it’s all worth it."

"We’re infatuated at looking at the tool instead of thinking ‘Why are people feeling this way? Why are people feeling this way, where they want to do evil things?’ We’re only looking at the gun stuff."