It's been a little over a week after 26-year-old Christopher Harper Mercer opened fire on a college classroom killing nine people.
President Obama will be in Roseburg, Oregon today to meet with families of the victims. This is not the first time he's had to do this. There have been 11 mass shooting during his time in office.
But what if there was a way to stop mass shootings before they start? That's the goal of a team of mental health and law enforcement specialists who work with campuses and offices across the country.
Stephen White is a psychologist and president of Work Trauma Services in the San Francisco Bay area. He works with businesses and college campuses to assess threats.
White says detecting a dangerous person often means following your gut.
"It's a situation of awareness, just common sense knowledge if you see something, say something," he said. "Something of concern -- where a person may be talking about violence in a way that's inappropriate -- they may be considering it and they leak out that intent," he said.
White says risk assessment professionals are trained to follow a series of steps in order to determine whether someone is just having a bad day, or if there is legitimate cause for concern. Many of them look for something called "leakage."
"Somebody might make a reference to violence and say, 'You know, I understand how that guy in Oregon felt.' In fact, the guy in Oregon said he understood how the guy in Roanoke Virginia felt," he said. White says a troubled person might signal their intent more clearly in the days immediately leading up to a planned attack.
When a campus faculty member identifies a person of concern, White says school police might compare the student's behavior to a list of known risk factors.
"And then -- after perhaps doing some collateral interviews -- somebody with the skill set will ideally sit down with the student and say 'look, we're concerned about you, we're concerned about some of the things you're saying, and we need to talk to you.' "
White says risk assessment professionals are always respectful, but also direct.
"We don't avoid asking them, 'Do you have these kinds of thoughts? Are you thinking about this? Do you have any thoughts of hurting yourself as well as hurting others?' "
White says many shootings have been prevented using this approach, but he adds "you never hear about them."
Press the blue play button above to hear more about violence prevention and to find out how mental illness factors into an assessment.