JACKSONVILLE, Fla. - Mental health is again in the national spotlight following the massacre at a South Florida high school.

Seventeen people were killed when Nikolas Cruz, 19, allegedly opened fire on his classmates at Marjory Stoneman Douglas High School in Parkland, Fla.

Following the shooting, several students said they weren’t surprised to learn Cruz was the suspect.

“He’s just always been a really crazy kid,” one student told reporters. “I heard some people say that one day he would’ve done this, and unfortunately I think that was today.”

The warning signs were there; disturbing material posted on social media, expulsion for fighting and the sudden death of his adoptive mother three months ago.

“It’s very troubling that we weren’t able to intervene a lot sooner and put things in place to provide the therapy and treatment for this individual,” Dr. Tracy Alloway, a University of North Florida psychology professor, said.

Alloway said the trauma of his mother’s death could have triggered more severe mental health issues.

“While the external ones were easier to spot and he as expelled for those reasons, we missed some of those internal ones,” she said. “Which we should have been able to intervene and refer him on, at least to see someone, to talk to someone.”

Students reported Cruz as having a history of troubling behavior. Alloway said because of that, someone should have stepped in immediately after his mother’s death.

“And offer bereavement counseling, to offer an opportunity for him to discuss his grief,” she said. “Because I think what might have happened is that he has first internalized that grief and then externalized that in those negative behaviors in the classroom and the school setting.”

Alloway added it’s critical for schools to keep an eye on students for troubling behavior and intervene as early as possible.

“I think at schools we need to be vigilant and be mindful of these kinds of symptoms,” she said. “And while it’s school policy to expel someone for this behavior, we also need to make recommendations that they see someone. That they get treatment and support.”

That’s not to say, however, that teachers should be providing counseling. Rather, Alloway said they should refer students and parents to trained professionals.

“What can we do in a proactive setting?” she said. “And that is when we notice the symptoms, because those were noticed, intervene right away.