Across the country, Americans are once again grieving the loss of young lives due to gun violence after a 15-year-old brought a gun to his Michigan high school and opened fire and killed at least four people. The teenager identified as Ethan Crumbley has been charged with 24 crimes, including terrorism and first-degree murder, Oakland County Prosecutor Karen McDonald announced Wednesday.

The Oxford High School sophomore faces one count of terrorism causing death, four counts of first-degree murder, seven counts of assault with intent to murder, and 12 counts of possession of a firearm in commitment of a felony. According to CNN, he will be tried as an adult and could be sentenced to life in prison.

McDonald noted that the terrorism charges were appropriate in this case because of the number of people who have been affected by the crime. Alongside the four deaths, at least seven others were injured.

“What about the children who ran, screaming, hiding under desks?” McDonald said. “What about all the children at home right now who can’t eat and can’t sleep and can’t imagine a world where they could ever set foot back in that school? Those are victims, too, and so are their families, and so is the community—and the charge of terrorism reflects that.”

McDonald and law enforcement officials said Wednesday that they found evidence that Crumbley both planned the attack and purposefully set out to kill students. In an arraignment hearing, Oakland County Sheriff’s Lt. Tim Willis shared that evidence from the suspected shooter’s cellphone includes two separate videos the teenager made the night before the incident “wherein he talked about shooting and killing students the next day at Oxford High School.”

Additionally, a journal was recovered from the suspect’s backpack, which detailed his desire to “shoot up the school, to include murdering students.”

“There are facts leading up to the shooting that suggest this was not an impulsive act,” McDonald said. “We have charged four counts of first-degree murder, which require premeditation. And I am absolutely sure after reviewing the evidence that it isn’t even a close call. It was absolutely premeditated.”

A press conference was held Friday to provide updates on the case and present charges against the shooter’s parents, who McDonald had previously said acted “far beyond negligence.” At the start of the press conference, McDonald noted that, while the shooter was the one who entered the school and pulled the trigger, “there are other individuals who contributed to this.” She said: “It’s my intention to hold them accountable.”

The gun used in the attack was purchased by Crumbley’s father four days beforehand, on Nov. 26, the Associated Press reported. After investigations into the parents, charges were also brought upon them.

The parents, James and Jennifer Crumbley, each face four counts of involuntary manslaughter, USA Today reported.

The gun “seems to have been just freely available” to Crumbley, McDonald told WJR-AM on Thursday. She noted that the gun was left in an unlocked space. “The parents were the only individuals in the position to know the access to weapons.”

According to CNN, Ethan Crumbley posted about his gun on social media, and his mother also created a post noting that her son was “testing out his new Christmas present.” Jennifer Crumbley was found to be aware that her son may use the gun in school. When the news of the active shooter had been made public, Jennifer Crumbley texted her son, “Ethan, don’t do it,” McDonald said. “James Crumbley called 911 reporting that a gun was missing from his house, and he believed his son may be the shooter,” McDonald added.

Additionally, a teacher also reported that Crumbley was found searching for ammunition on his phone during class on Nov. 21. His mother was contacted by school officials then.

“Jennifer Crumbley was contacted via voicemail by school personnel regarding the son’s inappropriate internet search. School personnel indicate they followed that voicemail up with an e-mail, but received no response from either parent,” McDonald said.

“Thereafter, Jennifer Crumbley exchanged text messages about the incident with her son on that day, stating, ‘lol, I’m not mad at you, you have to learn not to get caught,'” McDonald added.

​​A lot has been revealed in the last few days in regards to the case, officials found that Crumbley also met with school officials the day before and day of the shooting for “behavior in the classroom that they felt was concerning.” While details were not released on what exactly the behavior was, the gun he used to shoot his peers was in his custody at the time of the Nov. 30 meeting.

Superintendent of Oxford Community Schools, Tim Throne, said no disciplinary action was necessary for the alleged shooter prior to the shooting. Throne released a video message Thursday night.

Since the shooting, multiple copycat threats have been presented across the state of Michigan. According to the Detroit Free Press, a 17-year-old student in Southfield, about 30 miles from Oxford High School, was arrested Thursday with a semi-automatic pistol. At another school in the state, a bomb threat was made.

“If you’re making threats, we’re going to find you,” Bouchard said during a news conference Thursday. “It is ridiculous you’re inflaming the fears and passion of parents, teachers, and the community in the midst of a real tragedy.”

The FBI and Secret Service are also investigating threats across the state of Michigan.