The Secret Service analyzed 173 mass casualty attacks. Here's what they found.

Contributing sentiments towards policy:

54% :Over 21,000 organizations - including schools, houses of worship, businesses, law enforcement agencies and even sports leagues, like the NBA and MLB - have signed up for virtual training issued by the Secret Service, according to Alathari.
40% : Nearly one-third of the attackers detailed in the Secret Service study had at least one contact with law enforcement that did not result in arrest, including attackers who had engaged in acts of domestic violence (23%), violent crimes (23%), and non-violent crimes (22%).
39% : Just over one-third of the attackers had a history of using illicit drugs, misusing prescription medications or abusing substances like alcohol or marijuana, which often led to "negative consequences because of their substance use, including criminal charges, professional or academic failures, court-ordered programs, and evictions," according to the report.

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