A fourth student from Oxford High School in Oxford, Ohio, has died from gunshot wounds suffered in a Tuesday attack at the school.
The Detroit Free Press reports that Justin Shilling, 17, died Wednesday at a hospital in Pontiac.
Investigators were continuing to try to determine what led a 15-year-old sophomore to bring a semiautomatic handgun to the school and open fire Tuesday afternoon. Four students are dead; six students and a teacher were wounded.
Sheriff Michael Bouchard told CNN that agents found writings that contain the suspect's thoughts.
Video from the school shows the assailant was "shooting people at close range -- oftentimes toward the head or chest," Bouchard says.
Earlier:
Three students were killed and eight other people wounded in a shooting attack Tuesday afternoon at Oxford High School in Oxford, Mich.
CNN reports the three killed are students--two girls, 14 and 17, and a boy, 16, Oakland County Undersheriff Michael G. McCabe says. One of those wounded in the gunfire is a teacher; all of the others are students.
The Detroit Free Press later identified the dead students as: Tate Myre, 16; Hana St. Juliana, 14, Madisyn Baldwin, 17.
The alleged shooter is in custody and has been identified as 15-year-old boy who is a sophomore at the high school, McCabe says. His name was not disclosed.
The 15-year-old sophomore is being held at Oakland County Children's Village, a juvenile detention facility. He was placed on suicide watch and was being checked on every 15 minutes, County Executive David Coulter said.
Of those injured, the 47-year-old teacher with a grazing bullet wound had been discharged, while the children ages 14 through 17 years old were in conditions ranging from stable to critical, with injuries to extremities, chests, necks and heads. One 14-year-old girl was on a ventilator. Several other teachers and students were shot, some are in critical condition.
Other students were hurt in the evacuation, but had non-life-threatening injuries, the sheriff said.
It was unclear whether the suspect had targeted anyone. Some said he was bullied.
The incident unfolded in about five minutes and police said the shooter, who was not injured, was arrested after deputies stopped him coming down a hall with a 9mm handgun with seven rounds of live ammunition.
CNN also reports two 15-round magazines were found at the scene, at least 12 rounds were fired.
Oakland County Sheriff Mike Bouchard said the suspect's father purchased the handgun just four days ago.
Police have not uncovered a motive for the attack, McCabe says.
Oxford is about 40 miles north of Detroit.
