Plotters of school killings tend to tip off someone in advance
Los Angeles Times - 12/23/2012
“There are hundreds of thousands of students who fit the profile of the school shooter and wouldn’t hurt anybody,” said Jack Levin, a Northeastern University sociologist and criminologist who studies mass murder.
One reason the description is so broad is that school shootings are rare. More Americans are struck by lightning each year than killed in rampage shootings.
The number of mass murders — defined by the FBI as having at least four victims — has been stable over the last three decades at about 20 attacks and 100 to 150 victims a year, Levin said. The widespread perception of a rise comes from the media attention the killings receive, he said.