By Tony Hanson

PHILADELPHIA (CBS) — Police chiefs from around the world are meeting in Philadelphia this week for the 120th annual conference of the  International Association of Chiefs of Police.

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And among the priority issues being addressed is an increase in the number of mass shootings and an evolving tactical response to these “active shooter” situations.

US attorney general Eric Holder, in his opening address, told the chiefs that between 2000 and 2008 there were an average of five active-shooting incidents per year, but the number was rising rapidly.

“Now, alarmingly, since 2009, this annual average has tripled,” Holder said. “We’ve seen at least 12 active shooter situations, so far, in 2013.  And even more troubling, these incidents seem to be getting more and more deadly.”

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And he says post-incident analysis has led to a change in response tactics: from contain-and-wait to a more aggressive response.

“To save lives, the first officers to arrive must sometimes be the first ones to directly engage an active shooter,” Holder acknowledged.

And Philadelphia’s police commissioner, Charles Ramsey, says that it requires training, training, and more training — of all officers, not just SWAT officers, to deal with these situations.

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