ALEXANDRIA, Va. — Two-thirds of suspects in mass casualty attacks in the United States suffered from some form of mental illness, and nearly all of them engaged in threatening or suspicious communications beforehand, the Secret Service concluded in an analysis Tuesday.
The analysis covered 27 attacks in 2018 that left 91 people dead and 107 injured at office buildings, schools, a synagogue and other prominent public spaces, scattered from a sidewalk in Portland, Oregon to a high school Parkland, Florida.
The Secret Service identified 28 such attacks in 2017.
Federal investigators found that 67% of suspects displayed symptoms of mental illness or emotional disturbance, up slightly from last year’s 64%. In at least 93% of last year’s incidents, authorities found that the suspects had a history of threats or other troubling communications, up from 86% in 2017.
And in more than three-quarters of all cases – 78% – suspicious communications elicited concerns for the safety the attackers or others.
“Because these acts are usually planned over a period of time, and the attackers often elicit concern from the people around them, there exists an opportunity to stop these incidents before they occur,” the report concluded.
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Citing numerous cases in which the attackers engaged in threatening communications before their strikes, Secret Service Director James Murray and Lina Alathari, chief of the agency’s National Threat Assessment Center, appealed for the public’s help to thwart future assaults.
“We need to let people know who they can reach out to,” Alathari said Tuesday.
The 2018 Parkland high school attack, which reinvigorated a national debate on gun safety, stands as perhaps the most chilling of the cases in which others called attention to the troubled gunman before he struck.
Social workers, mental health counselors, school administrators and law enforcement all had been warned about Nikolas Cruz’s deteriorating mental state and risk of violence before he launched the attack that killed 17 and injured 17 others.
About a month before the attack, the FBI received a tip about Cruz and his “desire to kill people,” but the information was never forwarded for investigation, the bureau later confirmed.
Since Parkland, Alathari said Secret Service threat analysts were dispatched to provide training at FBI call centers to assist operators in assessing tip information.
“Prevention is everyone’s responsibility,” she said, adding that the FBI invited the additional training.