A new study by the Secret Service shows that students who carry out or attempt acts of violence at their schools using guns or knives almost always exhibit some clear warning signs beforehand — those signs are just often missed or ignored.

The study analyzed 41 instances of school violence by students; 25 of them involving guns, and 16 of them involving a bladed weapon of some sort, and some of those 41 including combinations of weapons.

What the study found was that students who committed these acts were often bullied, exhibited psychological or behavioral disorders, and often made direct threats of violence before their attacks.

"These are not sudden, impulsive acts where a student suddenly gets disgruntled," said Lina Alathari, head of the U.S. Secret Service National Threat Assessment Center, to the Associated Press. "The majority of these incidents are preventable."

According to the study, 91 percent of the attackers showed mental health issues that were either psychological, behavioral, or neurological/developmental, and half of them exhibited more than one category, usually a combination of psychological and behavioral.

Eighty percent of the attackers were bullied, with 57 percent of them having been victims of a long pattern of bullying over the course of weeks, months or years.

The clearest warning signal for these violent attacks are threats. At least 77 percent of them made threats before their attack, and 66 percent of them made threats that "gave some level of imminence" to the attack. Eighty percent of the attackers in the study displayed behaviors that caused concern to bystanders.

Other common factors displayed included absence from school beforehand, often due to suspension, a narcissism that led the student to seek power and fame through violence, and a history of school disciplinary actions and law enforcement encounters.

Prevention is important in these situations because most school attacks last for a minute or less, and police rarely arrive before the attack is over. So, by the time an attack starts, there is little that can be done to prevent some injury or loss of life.

"We focus on the target so that we can prevent it in the future," Alathari said.

(H/T: Hot Air)