The 15-year-old suspect who fatally shot three students and injured seven others and a teacher at Oxford High School north of Detroit on Tuesday used a gun purchased by his father on Black Friday, according to the local sheriff. The sophomore was in possession of the 9mm Sig Sauer SP2022 pistol and two 15-round magazines, one of which had seven rounds of ammunition remaining, when authorities arrested him within minutes of arriving at the school, Oakland County Sheriff Mike Bouchard said late Tuesday, per the Detroit Free Press. "He had a loaded firearm," Bouchard said. "He was coming down the hall. That again, I believe, interrupted what potentially could have been seven more victims."
The sheriff said a third magazine purchased by the suspect's father hadn't been found but was probably at the school. He added that a preliminary survey of shell casings suggested the suspect fired at least 12 rounds. Hours earlier, Undersheriff Mike McCabe suggested the shooter fired 15 to 20 rounds. Though some parents described rumors of violence to come at the school, which prompted some children to remain at home Tuesday, per the Free Press and Time, Bouchard said he wasn't aware of any credible threats of violence in the lead-up to the shooting. Authorities downplayed an incident at the school weeks earlier, in which a deer head had been thrown from a roof, saying it involved a different student, per Time.
However, Bouchard said the suspect had posted a photo of the weapon online during what appeared to be target practice. Authorities are pouring over the suspect's cellphone and social media posts, as well as surveillance footage from the 1,700-student school for clues to a motive. "The person that's got the most insight and the motive is not talking," he added, per Time. The suspect's parents, who've visited the teen in the juvenile detention center in which he's held, have also declined to speak to law enforcement, per the Free Press. Asked whether the parents could face charges related to the firearm, Bouchard said that would be "up to the prosecutor." (Read more school shooting stories.)