The gunman accused of killing 17 people at a Florida high school Wednesday had previously attended the school, where he was known as a “weird kid” and “loner” who was expelled for getting into a fight with his ex-girlfriend’s new beau, a current student said.

Nikolas Cruz, 19, arrived at Broward County Jail early Thursday morning after federal and local investigators questioned him for several hours. He was charged with 17 counts of premeditated murder in the shooting at Marjory Stoneman Douglas High School after being taken into custody “without incident” Wednesday by Coconut Creek police in a Coral Springs neighborhood just a few miles from the high school itself.

Nikolas Cruz was booked into Broward County Jail on 17 counts of premeditated murder. On the right is his yearbook picture. (Broward County Sheriff’s Office/Marjory Stoneman Douglas High School)

“All he would talk about is guns, knives and hunting,” Joshua Charo, 16, a former classmate, told the Miami Herald. “I can’t say I was shocked. From past experiences, he seemed like the kind of kid who would do something like this.”

Police said Cruz, who was identified as the only possible gunman, had been taken to the hospital for a period of time after his arrest because he “exhibited labored breathing.”

The motive behind the massacre was not immediately clear. Lawmakers and officials suggested the shooting may have been planned. Police said they are planning a 10:15 a.m. Thursday news conference. Cruz is also expected to make his first court appeared at 2 p.m.

Marjory Stoneman Douglas High School will be closed on Thursday and Friday.