WASHINGTON (AP) — Attorney General Eric Holder said Monday the average number of mass shooting incidents has tripled in recent years.

Between 2000 and 2008, the U.S. experienced an average of five mass shootings every year. Since then the annual average has tripled, Holder said. So far in 2013, there have been at least 12, he said.

According to Justice Department figures on mass shootings, 404 people were shot and 207 people were killed from 2009 to 2012. From 2000 to 2008, 324 people were shot and 145 were killed.

In remarks to the annual conference of the International Association of Chiefs of Police, the attorney general said that in the past decade, the Justice Department has helped train 50,000 front-line officers, more than 7,000 on-scene commanders and over 3,000 local, state and federal agency heads on how to respond to active shooters.

To disrupt planned shootings and other attacks, the FBI’s Behavioral Threat Assessment Center works every day with local police and other levels law enforcement to assess people who may be contemplating violence. Since 2011, the center has reported hundreds of successful disruptions, including an anticipated 150 this year alone, Holder said.

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