Chicago had 14 mass shootings, while Baltimore had 10 and New Orleans had 7. “And there’s some steps we could take, not to eliminate every one of these mass shootings, but to improve the odds that they don’t happen as frequently”. This is a looser criteria than the Federal Bureau of Investigation definition of mass murder, which it describes “as a number of murders (four or more) occurring during the same incident, with no distinctive time period between the murders”. Six of the 17 cities are big, with more than 2 million residents. He says that by including situations where the shooter knows the victims – such as domestic or gang violence – the rate of annual mass shootings actually declined slightly from 2011 to 2014 when compared with the previous four years.

The New York Times, the Washington Post, Boston Globe, CBS News, MSNBC, and Newsday all claimed that the shooting in San Bernardino, California was the 355th mass shooting this year. Another mass shooting incident in Boston in the early hours of Thanksgiving Day took the life of a Massachusetts Bay Transportation Authority rail conductor.

Fox also criticized Mother Jones for having inconsistent criteria, sometimes breaking its own one-gunman rule to include the two-shooter massacres at Columbine High School and in San Bernardino in their total.

So with these different definitions of “mass shootings“, you get different headlines like these.

Following the recent tragic shooting in San Bernardino, it has become abundantly clear that mass shootings have become far too common in American culture. But it also raised a question about what we define as a mass shooting in the United States – particularly how many people must be harmed or killed – and the differences between regular shootings, mass shootings, mass killings and massacres.

In 1973, 47 percent of American households reported having at least one gun. The FBI doesn’t officially define mass shooting, but Knight notes an FBI study indicates just two of 160 active shooter incidents involved more than one gunman. “This type of mass shootings happens everyday here to our kids and nobody stops it, nobody does anything”. Responding officers found the other three near the site of the shooting. Those top states include Colorado, North Carolina and Missouri, which are key political swing states; Wisconsin, home of U.S. House Speaker Paul Ryan; and nine states that have congressional members serving on the House and Senate judiciary committees, which oversee gun control legislation.

Obama recently released a plan of action for gun control, the details of which have been released in a summary by The National Conference of State Legislatures.

“All of a sudden instead of being told to think about the evil person who did it, we are subconsciously told to think about the tool they used”, NRA news contributor and Navy Seal veteran Dom Raso said.