The teenager suspected of fatally shooting 10 people at a Texas high school Friday reportedly yelled out "surprise!" before opening fire.
Dimitrios Pagourtzis, 17, is being held on capital murder charges with no bond following the massacre at Santa Fe High School, where he is a student, according to reports.
A witness said he yelled "surprise!" as he burst into a first-period art class and unleashed a hail of bullets, according to a Fox 26 reporter.
Ten people, including nine students and one teacher, were killed, and 10 others were injured.
On social media, Pagourtzis posted a photo of a T-shirt reading, "Born to Kill." He also posted a picture of a gun and a knife. Another image shows a raincoat adorned with a German iron cross.
Gunshots rang out at the school just after 8 a.m.
A female student at the school described the confusion she felt even after hearing the shots.
"I was sitting in my classroom and I heard really loud booms," she said. "I didn't know what they were at first and then I realized what they were when I heard screaming."
Other students reported seeing victims with gunshot wounds.
Authorities say a substitute teacher pulled a fire alarm when he realized what was happening in a bid to alert others at the large campus. Aerial footage from the scene showed students lined up outside the school.
Police say they found pipe bombs and pressure-cooker bombs at the school, which is located south of Houston.
Law enforcement has also searched property related to the suspect, according to reports.
President Trump was among those tweeting about the shooting, saying, "Early reports not looking good. God bless all."