Gov. Gretchen Whitmer embraces Oakland County Executive Dave Coulter as the two leave flowers and pay their respects Thursday morning, Dec. 2, 2021, at Oxford High School in Oxford, Mich.

OXFORD TOWNSHIP, Mich.  — A prosecutor considering criminal charges against the parents of a boy accused of killing four students at a Michigan school said Thursday their actions went “far beyond negligence” and that the gun “seems to have been just freely available” to the teenager.

Ethan Crumbley, 15, has been charged as an adult with two dozen crimes, including murder, attempted murder and terrorism, for a shooting Tuesday at Oxford High School in Oakland County, roughly 30 miles north of Detroit.

Four students were killed and seven more people were injured, including a student who remained in critical condition.

“All I can say at this point is those actions on mom and dad’s behalf go far beyond negligence,” Oakland County prosecutor Karen McDonald said. “We obviously are prosecuting the shooter to the fullest extent. … There are other individuals who should be held accountable.”

The semi-automatic gun was purchased by Crumbley’s father last week, according to investigators.

“The parents were the only individuals in the position to know the access to weapons,” McDonald told WJR-AM. The gun “seems to have been just freely available to that individual.”

Jennifer and James Crumbley did not return a message left by The Associated Press.

Sheriff Mike Bouchard disclosed Wednesday that the parents met with school officials about their son’s classroom behavior, just a few hours before the shooting.

McDonald said information about what had troubled the school “will most likely come to light soon.”

Crumbley stayed in school Tuesday and later emerged from a bathroom with a gun, firing at students in the hallway, police said.

“I just can’t get to a space right now to blame anybody who worked at that school. They were terrorized,” McDonald said.

“Should there have been different decisions made?” she said when asked about keeping the teen in school. “Probably they will come to that conclusion. … Again, I have not seen anything that would make me think that there’s criminal culpability. It’s a terrible, terrible tragedy.”

The Oxford school district hasn’t commented on the meeting with Crumbley’s parents before the shooting.

There’s no Michigan law that requires gun owners keep weapons locked away from children. William Swor, a defense lawyer who is not involved in the case, said charging the parents would require a “very fact-intensive investigation.”

“What did they know and when did they know it?” Swor said. “What advance information did they have about all these things? Did they know anything about his attitude, things of that nature. You’re talking about a very heavy burden to bring on the parents.”

In 2020, the mother of an Indiana teen  was placed on probation for failing to remove guns from her home after her mentally ill son threatened to kill students. He fired shots inside his school in 2018. No one was injured but the boy killed himself.

In Texas, the parents of a student who was accused of killing 10 people at a school in 2018 have been sued over his access to guns.

Meanwhile, dozens of schools in southeastern Michigan canceled classes Thursday due to concerns about threatening messages on social media following the Oxford shooting. Some schools stayed open with a larger police presence.