Larry Copeland

USA TODAY

School shootings in the USA during the two years since the Newtown, Conn., massacre often involved a minor taking a gun from home and using it in a confrontation that started out as an argument, according to a new report by two groups who went to Washington, D.C., Tuesday seeking political action to prevent gun violence.

The two groups, whose definition of school shootings includes those those involving gang violence, unintentional shootings and suicides, used news accounts to compile a list of 95 shootings that occurred in 33 states; 23 of the incidents resulted in at least one death. All told, the shootings caused 45 deaths and 78 gunshot injuries, according to the report from Everytown for Gun Safety and Moms Demand Action for Gun Sense in America.

"Ninety-five school shootings is 95 too many," said U.S. Rep. Mike Thompson, a California Democrat who chairs the House's Gun Violence Prevention Task Force. "We must do more to keep the gunfire out of our children's classrooms, hallways and gymnasiums. That means keeping guns out of dangerous hands in the first place, and passing comprehensive background checks is the first step."

Forty-nine of the shootings occurred at K-12 schools and 46 on college or university campuses.

Of the 40 K-12 shootings in which the shooter's age was known, 28 were committed by minors. Of the 16 K-12 shootings where it was possible to determine the source of the firearm, 10 of the young perpetrators got their guns from home, the report says. In some cases, investigators in news accounts declined to say where the shooters obtained guns; other accounts did not provide the shooters' ages.

Shootings included incidents involving gang violence, unintentional shootings and suicides.

"School shootings ... erode the sense of security we should expect from our educational institutions in this country. Two years ago, the NRA called for arming teachers. That's their solution -- more guns for everyone, everywhere, anytime," said John Feinblatt, president of Everytown for Gun Safety. "Instead, we can and should do more to prevent gun violence. That's why we're fighting for common-sense public safety measures that respect the Second Amendment and keep guns out of the wrong hands."

The NRA did not respond to a request for comment.

Over the past two years, there were an average of two school shootings a month at K-12 schools, according to the report. During the past three months, there were 17 shootings, including one week -- Sept. 24-30 -- in which there were five incidents in five states: Texas, Tennessee, Indiana, North Carolina and Kentucky.

"We do not send our children to school to learn how to hide from gunmen, nor should we expect sharpshooting to be a job requirement for educators," said Shannon Watts, founder of Moms Demand Action. "You may not have heard about all of these shooting incidents on the national news, but when a lockdown is announced over a school intercom, for whatever reason, it strikes fear across the community. ... It's time for our elected leaders to take a stand for the safety and future of our children."

Everytown for Gun Safety, which calls itself the nation's largest gun violence prevention organization, was born this year out of the merger between Mayors Against Illegal Guns, founded in 2006 by then-mayor Michael Bloomberg of New York and 14 other mayors, and Moms Demand Action for Gun Sense in America, which was begun by Watts, an Indianapolis stay-at-home mom, in response to the Sandy Hook school shooting.

On Dec. 14, 2012, Adam Lanza, 20, shot and killed his mother, then drove to Sandy Hook Elementary School and launched the nation's deadliest mass shooting at a high school or grade school. He then shot and killed himself.