WAPO FACTCHECK: Obama’s Inconsistent Claim On The Frequency Of Mass Shootings. “Comparing to the U.S. to Europe (including OECD and non-OCED countries) from 2009 to 2015 shows the rate of mass shootings in the United States and Europe are about the same, Lott said. (Lott uses the FBI definition of four or more killings in a public space, excludes gang or crime-related activity, and includes acts identified as terrorism.)”