Updated

Ethan Crumbley, the 15-year-old suspect accused of opening fire at his Michigan high school, pleaded not guilty on Wednesday to 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 the commission of a felony. 

The sophomore, who is being charged as an adult, allegedly fired more than 30 rounds in the hallways of Oxford High School on Tuesday shortly before 1:00 p.m., killing four students and wounding seven others, including a teacher. 

He appeared in Oakland County Court by video on Wednesday, slumped over in a vest, white mask, and glasses. 

Michigan school shooting suspect Ethan Crumbley

Ethan Crumbley is being held without bond on murder, terrorism, and other charges.  (Oakland County Sheriff's Office)

Mark Keast, an assistant prosecuting attorney in Oakland County, told Judge Nancy Carniak that he doesn't "have the words to describe how horrific" the surveillance video of the shooting is. 

"He methodically and deliberately walked down a hallway, aimed the firearm at students and fired it," Keast said. "After children started running away from the defendant, he continued down the hallway, again at a deliberate and methodical pace, pointing and aiming inside classrooms and at students who hadn’t had the opportunity to escape."

Ethan Crumbley allegedly shot and killed four students and wounded seven others at Michigan's Oxford High School

Ethan Crumbley allegedly shot and killed four students and wounded seven others at Oxford High School. 

Judge Carniak ordered Crumbley to be held without bond and transferred to Oakland County Jail, where he will be separated from adults. 

MICHIGAN HIGH SCHOOL TEEN KILLED IN SHOOTING WAS 'HERO,' CLASSMATES SAY

Lt. Tim Willis told the judge that Crumbley recorded videos on his phone the night before the incident in which he "talked about shooting and killing students the next day at Oxford High School."

"Further, a journal was recovered from Ethan’s backpack also detailing his desire to shoot up a school to include murdering students," Willis said. 

Crumbley's parents went to Oxford High School about two to three hours before the shooting to meet with their son and school officials over behavioral issues in the classroom. 

"The parents were brought in the morning of the shooting and had a face-to-face meeting with the school," Oakland County Sheriff Michael Bouchard said. 

"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."

Michigan school shooting suspect Ethan Crumbley's parents

Ethan Crumbley's parents appeared in court by video on Wednesday. 

Crumbley also had to meet with school officials the day before the shooting "over behavior in the classroom that they felt was concerning."

Oakland County Prosecutor Karen McDonald noted that the terrorism count is not a "typical" charge, but she said that it is necessary to get justice for all the victims in this shooting. 

"The children that I have just listed and those that were injured, they’re the victims in the first-degree murder charges and assault with intent to murder," McDonald said. 

"But what about all these other children? What about all the children who ran, screaming, hiding under desks? 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 step foot back in that school. Those are victims too."

GUN USED IN MICHIGAN SCHOOL SHOOTING PURCHASED BY SUSPECT'S FATHER ON BLACK FRIDAY

The suspect used a 9mm Sig Sauer, according to police, which the boy’s father bought on Black Friday, just four days before the shooting. A motive has not been announced. 

McDonald said that her office is looking at charging the parents and "that decision will be made swiftly."

The suspect has declined to speak with authorities following his arrest and his parents have hired an attorney. 

"There is no conversation that’s going on and no cooperation at that level," Bouchard said Tuesday. 

At least 30 shell casings were found at the scene and the suspect still had 18 live rounds when deputies apprehended him. 

Crumbley was apprehended by police within five minutes of the first 911 call, Bouchard said. 

CLICK HERE TO GET THE FOX NEWS APP 

Four students died due to the shooting. Bouchard identified three of the students on Tuesday as 16-year-old Tate Myre, 14-year-old Hana St. Juliana, and 17-year-old Madisyn Baldwin. 

The fourth student died on Wednesday morning and was identified as 15-year-old Justin Shilling. 

Three of the injured victims – a 15-year-old male, a 17-year-old male, and a 47-year-old teacher – have been discharged from the hospital. Four injured victims are still hospitalized.