Police vehicles remain parked outside of Oxford High School on December 01, 2021 in Oxford, Michigan. Yesterday, three students were killed and eight others were injured when a gunman began shooting at the school. A 15-year-old sophomore, believed to be the only gunman, is in custody. | Getty Images/Scott Olson

Hours before the 15-year-old Oxford High School shooting suspect went on a deadly rampage at the Michigan school on Tuesday, his parents met with school officials about "concerning" behavior in class, which they engaged him about a day earlier, according to investigators.

The revelation was made by Oakland County Sheriff Michael Bouchard at a press conference Wednesday. Bouchard shot down online allegations that police had been alerted earlier this month about threats of violence alluded to in two letters from the school dated Nov. 4 and Nov. 12.

Bouchard said the concerns raised in those letters had nothing to do with Oxford Schools and that "we received no information about this individual prior to the shooting."

"We also were told that the school had some information or some kind of contact with the individual" over behavior in the classroom "they felt was concerning," said Bouchard. He noted that there was also no evidence to support claims that the 15-year-old suspect was being bullied.

"We have since learned that the school did have contact with the student the day before and the day of the shooting for behavior in the classroom that they felt was concerning," he added.

"In fact, the parents were brought in the morning of the shooting and had a face-to-face meeting with the school. The content of that meeting, obviously, is part of the investigation, but we did not learn of that meeting nor of the content of that meeting until after the shooting and during this investigation."

Beginning at approximately 12:51 p.m. Tuesday, Ethan Crumbley allegedly emerged from a bathroom at Oxford High School and went on a shooting rampage in a hallway, leading to the deaths of four students and the injuring of seven other people.

Oakland County Prosecutor Karen McDonald announced Wednesday that Crumbley was charged with four counts of murder for the deaths of students Tate Myre, 16; Hana St. Julian, 14; Madisyn Baldwin, 17; and Justin Shilling, 15.

He was also charged with one count of terrorism causing death, seven counts of assault with intent to murder and 12 counts of possession of a firearm in the commission of a felony.

McDonald said there still remains a lot of evidence to review and more charges could be forthcoming. Crumbley used his father's 9mm semi-automatic handgun purchased on Black Friday to carry out the massacre. McDonald said she was considering charges against Crumbley's parents — James, 45, and Jennifer Crumbley, 43 — who she described as "difficult."

"We know owning a gun means securing it properly, locked up, and keeping ammunition separate and not allowing access to other individuals, especially minors," McDonald explained.

Ethan Crumbley's older half-brother, Eli Crumbley, 18, told The Daily Mail that he was surprised by the actions of his sibling. He described the younger Crumbley as a quiet, happy person who stayed away from trouble.

"The Ethan I knew was just a smart boy who just seemed like an average kid. There was nothing that ever stood out to me. He'd never get suspended from school, or detention," he told the publication. "He didn't suffer depression or anything like that. He woke up happy, went to school, came home and played games."

Eli Crumbley, who lived with his brother, father and stepmother in Oxford until last March, said he was not aware that his younger brother had a gun or that he faced any bullying.

"I didn't know he had a gun till after this happened. It's still hard to believe. I can't believe it," he said.

"When I was living there, nothing seemed off. We'd just walk to the bus stop in the morning, go to school, come home, maybe play some football outside or basketball. We'd just chill, wouldn't do much," he said.