PARKLAND, Fla. — Nikolas Cruz posted “very, very disturbing” material on his social media before allegedly killing more than a dozen people Wednesday at Marjory Stoneman Douglas High School, Broward County Sheriff Scott Israel reported Wednesday night.

Although Israel would not go into details about the posts or on which site they were found, an ex-schoolmate recalled Cruz posting on Instagram about killing animals and said he talked of doing target practice in his backyard with a pellet gun.

Israel said Cruz, 19, had been expelled from Marjory Stoneman Douglas for disciplinary reasons but he doesn’t know the specifics.

But Victoria Olvera, a 17-year-old junior, says Cruz was expelled last school year after a fight with his ex-girlfriend’s new boyfriend.

School officials haven’t confirmed that account, but say Cruz was attending another school in Broward County after his expulsion.

One 17-year-old junior, Dakota Mutchler, says he used to be friends with Cruz but hadn’t seen him in more than a year after his expulsion. He says of Cruz: “He started progressively getting a little more weird.”

Student Daniel Huerfano told The Associated Press he remembers seeing Cruz walking around the school with his lunch bag, adding, “He was that weird kid that you see … like a loner.”

A school superintendent, Robert Runcie, told reporters he didn’t know of any concerns raised about Cruz.

Florida Gov. Rick Scott joined law enforcement agents near the site of the shooting and offered his condolences to the victims’ families and survivors. He said the attack that claimed 17 lives “is just absolutely pure evil.”

Scott told reporters Wednesday evening he can’t imagine what the families of the victims are going through. He also said he would be visiting hospitalized survivors.

Sheriff Scott Israel of Broward County also said at the news conference that 12 of the dead were identified immediately but some weren’t carrying identification and that slowed confirmation efforts.

Cruz was arrested without incident in nearby Coral Springs, Israel said. He was treated for injuries at a hospital before was taken to jail.

— Associated Press with Staff Reports; Screencap, YouTube