On Thursday, the latest installment in a long-running series of school shootings in America took place at Umpqua College in Southern Oregon. The shooter reportedly entered the campus on Thursday with three weapons, including a long gun and handguns, and killed 10 people, while injuring seven more.

“It sounded like someone dropped something heavy on the floor, and everybody kind of startled…Everybody’s head kind of turned and looked at each other, trying to grasp what was happening, and someone said, ‘Those are gunshots,’” 23-year-old Umpqua student Brady Winder said to the New York Times.

While Sheriff John Hanlin of Douglas County initially declined to reveal the shooter’s identity in order to not, “give him the credit he probably sought,” multiple law enforcement officials have now revealed the shooter to be 26-year-old Chris Harper Mercer. According to a law enforcement official at the scene, Mercer had body armor with him and was heavily armed, seemingly ready for an extended gunfight. Mercer was later killed by local law enforcement officials.

“We arrived to find multiple patients in multiple classrooms. Law enforcement was on scene and had the shooter neutralized,” Douglas County Fire Marshal Ray Shoufler said to CNN.

According to multiple witnesses at the scene, the shooter specifically targeted Christians. Mercer, a self-described non-religious man, would ask who in the room was Christian, then when they stood up, he said, “good, you’re about to see God in a second,” then shot them. Despite being non-religious, many of his social media posts suggest that he was a sympathizer to the predominantly Catholic Irish Republican Army. In addition to this, he also posted messages in the past that were sympathetic to the man who shot two local news reporters in Virginia.

“I have noticed that so many people like him are all alone and unknown, yet when they spill a little blood, the whole world knows who they are. A man who was known by no one, is now known by everyone. His face splashed across every screen, his name across the lips of every person on the planet, all in the course of one day. Seems the more people you kill, the more you’re in the limelight,” Mercer said in a blog post.

The shooting has prompted an eruption of emotion nationwide, prompting responses from figures such as President Barack Obama himself. Thursday night, the former Illinois senator responded to the tragedy with an emotional statement, pleading with voters to act and crusade for stricter gun control laws. Mercer reportedly possessed 13 weapons, all of them purchased legally either by him or by a relative from a federal gun dealer.

“Our thoughts and prayers are not enough. It’s not enough. It does not capture the heartache and grief and anger that we should feel, and it does nothing to prevent this carnage from being inflicted someplace else in America next week, or a couple months from now,” Obama said in a statement at the White House.