Teen charged with murder, terrorism in Michigan school shooting as death toll rises to 4

A 15-year-old boy was charged Wednesday with murder, terrorism and other offences for a shooting that killed four fellow students and injured others at a Michigan high school, authorities said Wednesday, revealing that his parents were summoned just a few hours before the bloodshed.

The charges were announced a few hours after authorities reported the death of the fourth teen from Oxford High School, roughly 50 kilometres north of Detroit.

No motive was offered by Oakland County authorities for Tuesday's violence. But prosecutor Karen McDonald said the shooting was premeditated, based in part on a "mountain of digital evidence" collected by police.

"This was not just an impulsive act," McDonald said.

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 killing students.

Crumbley was charged as an adult with murder, attempted murder, terrorism causing death and gun crimes. During his arraignment, he replied, "Yes, I do," when asked if he understood the charges.

Defence attorney Scott Kozak entered a plea of not guilty.

"He deliberately brought the handgun that day with the intent to murder as many students as he could," assistant prosecutor Marc Keast said in successfully arguing for no bail and a transfer to jail from a juvenile facility.

The four students killed were identified as: Tate Myre, 16; Hana St. Juliana,14; Madisyn Baldwin, 17; and Justin Shilling, 17, who died Wednesday.

Another six unidentified students and a teacher were injured in the shooting. As of Wednesday afternoon, four had been treated and released, two were in stable condition and one, a 17-year-old girl, was in critical condition, according to the Oakland County Sheriff's Department.

Earlier, Sheriff Mike Bouchard told reporters that Crumbley's parents were called to the school Tuesday "for behaviour in the classroom that was concerning." The teen remained in school, and the shooting occurred a few hours later.

Bouchard didn't offer details about what had troubled school officials. He said investigators believe the gun was already in the school.

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

The shooting should be a wake-up call for new gun laws in a country that has become "desensitized to school shootings," McDonald told reporters.