'This was not an impulsive act': Teenager charged with terrorism after Michigan school shooting

A 15-year old boy has been charged with terrorism and murder after opening fire at his school in Michigan killing four and injuring several others, with police declaring: "This was not an impulsive act."

The police named the suspect as Ethan Crumbley and said his parents had been summoned to the school just hours before the attack took place.

No motive has been released but prosecutor Karen McDonald said the shooting was premeditated, based in part on a “mountain of digital evidence” collected by police.Oakland County Sheriff’s Lt. Tim Willis said during a court hearing for Ethan Crumbley that the boy recorded a video the night before the violence in which he discussed shooting and killing students.

A 16-year-old boy and two girls aged 14 and 17 died during the shooting. A fourth student died of his injuries on Wednesday.

Oakland County Undersheriff Mike McCabe said around 15 to 20 shots were fired by the shooter

Investigators say the 15-year-old was armed with a semi-automatic handgun bought last week by his father.

Sheriff Mike Bouchard said his parents were called to the school on Tuesday “for behaviour in the classroom that was concerning.”

The teenager remained in school, and the shooting occurred a few hours later.

“There is nothing that he could have faced that would warrant senseless, absolutely brutal violence on other kids,” the sheriff said.

Ethan Crumbley was arrested within minutes of police arriving at the school in response to a flood of 911 calls about the attack, which happened shortly before 1pm (local time).

A teacher who received a graze wound to the shoulder left the hospital, but seven students ranging in age from 14 to 17 remained hospitalised through the night with gunshot wounds, he said.

McDonald said the shooting should be a wake-up call for new gun laws in a country that has become “desensitised to school shootings,”

“We have to do better,” McDonald said. She said charges were being considered against the parents.

“Owning a gun means securing it properly and locking it and keeping the ammunition separate,” she said.

Oakland County Undersheriff Mike McCabe said at an earlier news conference Ethan Crumbley's parents advised their son not to talk to investigators.

In the US police must seek permission from a juvenile’s parents or guardian to speak with them.

“The person that’s got the most insight and the motive is not talking,” McCabe said.

He added he was aware of allegations circulating on social media that there had been threats of a shooting at the roughly 1,700-student school before Tuesday's attack, but he cautioned against believing that narrative until investigators can look into it.

He also downplayed the significance of an incident in early November when a deer head was thrown off the school roof, which he said was “absolutely unrelated” to the shooting.

The vandalism prompted school leaders to post two letters to parents on the school’s website this month, saying they were responding to rumours of a threat against the school but had found none.

Some students said they had heard vague threats “for a long time now” about plans for a shooting, raising concerns from parents about school safety.

President Joe Biden said his heart goes out to the families of the victims

The governor of Michigan, Gretchen Whitmer, also spoke at the news conference, saying, “I think this is every parent’s worst nightmare,” while choking up. President Joe Biden, before delivering remarks at a community college in Rosemount, Minnesota, said: "As we learn the full details, my heart goes out to the families enduring the unimaginable grief of losing a loved one".

Aerial shots over the school show victims being carried out on stretchers

The school was placed on lockdown after the attack, with some children sheltering in locked classrooms while officers searched the premises. They were later taken to a nearby grocery store to be picked up by their parents. The district said in a statement that all of its schools would be closed for the rest of the week.

Isabel Flores, a 15-year-old pupil at the school, told WJBK-TV that she and other students heard gunshots and saw another student bleeding from the face. They then ran from the area through the rear of the school, she said.

At a vigil at Lakepoint Community Church on Tuesday night, parents, students, teachers and the local community came together to grieve.

Pastor Jesse Holt said news of the shooting flooded in to him and his wife, including texts from some of the 20 to 25 students who are among the 400-member congregation.

“Some were very scared, hiding under their desks and texting us, ‘We’re safe, we’re OK. We heard gunshots, but we’re OK’. They were trying to calm us, at least that’s how it felt,” he said Tuesday night.

One student texted that she was hiding in a bathroom with a boy who also was seeking shelter.

After police arrested the shooter, the girl ran from the school and was taken in by someone living close by until her parent could pick her up, Mr Holt said.

“That’s our community,” he said. “That’s who we are”.