US Attorney General Eric Holder says mass shootings have tripled in the United States in recent years as another deadly shooting occurred at a Nevada middle school.
Holder said on Monday that an average of five mass shootings happened every year between 2000 and 2008 and the annual average has tripled since then.
He added that there have been at least 12 mass shooting incidents in the country so far this year.
On Monday, a student opened fire at a middle school in Nevada and killed a teacher and wounded two students before he was left dead.
“It’s too early to say whether he was targeting specific people or just going on an indiscriminate shooting spree,” Tom Robinson, deputy chief of the Reno Police Department, said.
Nevada Gov. Brian Sandoval said in a statement he was “deeply saddened to learn of the horrific shooting at Sparks Middle School this morning.”
The latest incident comes after the killing of 26 people at Sandy Hook Elementary School in Newtown, Connecticut last year ignited gun-control debate.
US Justice Department figures on mass shootings showed 404 people were shot and 207 people were killed from 2009 to 2012.
According to the department, 324 people were shot and 145 were killed from 2000 to 2008.
During his speech at the annual conference of the International Association of Chiefs of Police, Holder explained the Justice Department’s efforts in the past decade to stop the gun violence in the US.
He said the department has helped train 50,000 front-line officers, more than 7000 on-scene commanders and over 3000 local, state and federal agency heads on how to respond to active shooters.