A 15-year-old sophomore has been taken into custody after four students were killed and at least eight others injured in a mass shooting at a suburban high school in Michigan on Tuesday.
The suspected shooter, teenager Ethan Crumbley, was apprehended by police following the incident at Oxford High School in Oxford Township, a community of 22,000 people 30 miles north of Detroit, and a semi-automatic 9mm Sig Sauer handgun was seized.
Oakland County undersheriff Mike McCabe said the suspect had not offered any resistance when he was arrested, which he said took place within five minutes of the first 911 call being received, simply putting his hands on his head and surrendering.
A motive for the attack has not yet been established, according to the undersheriff, as the teen invoked his right to an attorney and declined to speak to officers, apparently on the instruction of his parents.
On Wednesday, Mr Crumbley appeared virtually in court to face the charges and plead not guilty. Asked by the judge if he understood the charges, he calmly said: “Yes, I do.”
Prosecutors told the judge that CCTV footage from the school showed Mr Crumbley “methodically and deliberately” walking the hallways and firing his pistol at fellow students.
The judge accepted prosecutors’ request to deny him bail and transfer him out of juvenile detention to the county jail because he could pose a threat to other minor prisoners.
The teenager was charged as an adult with one count of terrorism, four counts of first-degree murder, seven counts of assault with intent to murder, 12 counts of possession of a firearm in the commission of a felony.
Oakland County Prosecutor Karen McDonald said the charges stemmed from “undeniable” evidence that the attack was premeditated.’
Mr McCabe said investigators planned to examine his smartphone and social media posts as they search for clues pointing to a possible motive and that they have already executed a search warrant on his house, retrieving several items, notably a cache of weapons including long guns.
Speaking to CNN on Wednesday, Oakland County sheriff Michael Bouchard said: “It’s clear that he came out with the intent to kill people. He was shooting people at close range, oftentimes towards the head and chest… It’s just absolutely coldhearted murders.”
Mr Bouchard said investigators were examining writings belonging to the shooter obtained in the middle of the night that contain “some of his thoughts”.
“We can’t get the motive from the suspect that we have in custody, but we think we’ve got a path to get a lot of supportive information as to how and why this occurred,” he said.
Sheriff Bouchard said he was unaware of any previous run-ins with law enforcement by the suspect, adding that investigators had so far seen nothing to suggest a history of disciplinary problems.
He added that forensic technicians were collecting evidence from the crime scene, while detectives were gathering video footage from security cameras mounted around the school and interviewing witnesses and those acquainted with the suspect.
Because the suspect is under 18, he was initially moved to Oakland County Children’s Village, a juvenile detention centre where he was put under “suicide watch”.
The shooter is understood to have emerged from one of the school’s bathrooms at approximately 12.51pm bearing the pistol, which had been hidden in his backpack and was purchased by his father four days earlier.
Chilling footage subsequently emerging from the incident shows him firing off between 15 and 20 shots from multiple magazines as he stalks the school’s halls.
At one point, he is seen banging on a door and claiming to be a police officer in a bid to dupe people into coming out into the corridor, ordering someone to: “Just open the door bro.”
His fellow students are meanwhile seen running for cover and barring classroom doors with chairs.
Robin Redding, a mother of one of the teenagers at the school, caused a stir in the aftermath of the incident when she told the Associated Press: “This couldn’t be just random. Kids just, like they’re just mad at each other at this school.”
Her remark inspired rumours that the suspect might have issued overt threats in advance of his rampage but this was denied by Sheriff Bouchard, who said: “There was no prior information shared with the Sheriff’s Office or the School Resource Officer before the incident.”
Additional reporting by agencies