By Jim Melwert
PHILADELPHIA (CBS) -- A new report that takes a look at mass killings in the United States indicates that, despite the common perception, there has not been a rise in mass killings.
Data compiled by USA Today notes that 2013 saw 137 deaths from mass killings, slightly below the yearly average of 147.
The term "mass killing" is defined as the murder of four or more people, not including the murderer.
And the report says that while public massacres dominate the headlines, they only amount to 17 percent of mass killings.
Dan Romer, associate director of the Annenberg Public Policy Center at the University of Pennsylvania, wonders what effect the saturation news coverage has on subsequent incidents.
"There's clearly some effect of the coverage," he tells KYW Newsradio. "What we don't know is whether it actually encourages young people who are suicidal to go out and do the same thing."
The report finds that the vast majority of mass killings are family related -- usually a husband, a father, or son.
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