- After the Oxford school shooting, prosecutors said the suspect displayed warning signs.
- A psychologist said warning signs are too broad to predict if someone is going to commit violence.
- Joel Dvoskin told Insider schools need a strategy to conduct threat assessments to prevent shootings.
Identifying "warning signs" is often discussed to prevent school shootings, but focusing too much on warning signs may be an imperfect strategy.
"When you say 'what's the profile of a school shooter?' you're talking about somebody that feels despondent, is angry, maybe they're depressed," Joel Dvoskin, a clinical and forensic psychologist and professor at the University of Arizona, told Insider. "But you've just described half of Americans."
He said such indicators "apply in some cases to millions of people who are never going to hurt anybody."
When searching "warning signs of a school shooter" on Google, some of the top results list withdrawing from friends and family, loneliness, bullying, and anger issues — all of which are not unusual in adults or teenagers.
Even darker warning signs, like violent writings, bragging about access to weapons, and interest in past school shooters, do not necessarily indicate a person will commit violence.
"There are so many false positives" when using warning signs to profile a potential mass shooter, Dvoskin said.
Prosecutors said the suspect in the Oxford High School shooting in Michigan displayed warning signs, including posting about his gun and producing violent drawings.
Such signs should not be ignored, Dvoskin said, adding the most important sign is a person who says they are going to do something, which should always be taken seriously.
But he said schools need to have a proactive strategy to conduct "threat assessment," a practice that includes evaluating the larger picture to determine the likelihood of an imminent threat.
He said some schools train employees on this and consult with people who do threat assessment for a living whenever there is a warning sign, as simply identifying them is not enough.