Washington, July 10 (Xinhua/UNB) -- As many as two-thirds of suspects, or 67 percent exactly, displayed symptoms of mental illness or emotional disturbance when launching mass casualty attacks across the United States last year, according to a report released by the U.S. Secret Service on Tuesday.
In at least 93 percent of last year's attacks, authorities found that the suspects had a history of threats or other troubling communications beforehand, said the report, which covered 27 attacks in 2018 that left 91 people dead and 107 injured.
"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.
The Secret Service identified 28 such attacks in 2017, according to a USA Today report.