Washington AP

Attorney General Eric Holder said Monday the average number of mass shooting incidents in the U.S. has tripled in recent years. Between 2000 and 2008, the country 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.