A 15-year-old was charged on Wednesday with murder, terrorism and other counts for a shooting that killed four fellow pupils and injured others at a Michigan high school.
Ethan Crumbley is being charged as an adult with one count of terrorism causing death, four counts of first-degree murder and seven counts of assault with intent to murder, Oakland County Prosecutor Karen McDonald said at a news conference.
She did not reveal a possible motive for the shooting.
Ms McDonald said prosecutors are also considering charges for the suspect's parents.
Oakland County Undersheriff Mike McCabe told a news conference that two of those wounded in the shooting were undergoing surgery, and that the six others were in stable condition.
He identified the three pupils who were killed as a 16-year-old boy and two girls, aged 14 and 17. A fourth child, a 17-year-old boy, died from his injuries on Wednesday.
Authorities said they received a flood of 911 calls shortly before 1pm about an attack at Oxford High School in Oxford Township, a community of about 22,000 people to the north of Detroit, Michigan.
Mr McCabe said deputies took the suspected shooter into custody without incident within five minutes of arriving at the school and recovered a semi-automatic handgun and several clips of ammunition.
He said the suspect's parents visited him in custody and advised their son not to talk to investigators, as is his right.
Investigators were still trying to determine a motive for the shooting.
“The person that’s got the most insight and the motive is not talking,” he said at a news conference late Tuesday evening.
“Deputies confronted him, he had the weapon on him, they took him into custody,” Mr McCabe said, adding that teenager was not hurt when he was arrested.
Authorities did not immediately release the names of the suspected gunman or the victims. About 1,700 students attend the school.
Tim Throne, the superintendent of Oxford Community Schools, said he did not know yet know the victims’ names or whether their families had been contacted.
“I’m shocked. It’s devastating,” the superintendent told reporters.
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.
Isabel Flores told WJBK-TV that she and other students heard gunshots and saw another student bleeding from the face. Mr McCabe said investigators would be looking through social media posts for any evidence of a possible motive.
Robin Redding said her son, Treshan Bryant, is a 12th grader at the school but stayed home on Tuesday. She said he had heard threats of a shooting at the school.
“This couldn’t be just random,” she said.
Ms Redding did not provide specifics about what her son had heard, but she expressed concern with school safety in general.
“Kids just, like, they’re just mad at each other at this school,” she said.
Treshan said he texted several younger cousins in the morning and they said they did not want to go to school, and he had a bad feeling. He asked his mom if he could do his assignments online.
The teenager said he had heard vague threats “for a long time” about plans for a shooting at the school.
“You’re not supposed to play about that,” he said of the threats. “This is real life.”
Michigan Governor Gretchen Whitmer was one of several elected officials who expressed condolences to the victims.
“Gun violence is a public health crisis that claims lives every day. We have the tools to reduce gun violence in Michigan. This is a time for us to come together and help our children feel safe at school,” Ms Whitmer said.