I was reading an article from the BBC about the Highlands Ranch School shooting and they made the following claim
This is believed to be the 115th mass shooting in the US in 2019.
This was on the 8th May 2019.
Is the Highlands Ranch School shooting the 115th mass shooting in the US in 2019 as of 8th May 2019? What is the BBC considering to be a mass shooting?
If you use the definition of "mass shooting" used by Gun Violence Archives, this is the 115th mass shooting in the United States in 2019.
I have twice previously answered questions regarding statistics in mass shootings in On average in the US, is there a mass shooting 9 out of every 10 days? and Are handguns used in 80% of mass shootings?. For the sake of brevity, the conclusion I've reached in each question is that, due to disagreement as to how to actually define a mass shooting, people can change their definition to make the mass shooting statistics say whatever they want to.
In the case of this article, they are most likely using statistics from Gun Violence Archives. I've previously established that GVA uses one of the loosest definitions of mass shootings, which requires a combination of 4 people to be wounded or killed during a single incident.
This definition leaves out several of the requirements used by other agencies to define a mass shooting:
Note that, while this is the loosest definition of a mass shooting, it is not necessarily wrong, as stated by experts quoted in this Politifact Article from 2017.
Gun control groups say it’s arbitrary to distinguish between a death and an injury. They point out a significant problem: Some shootings that injure a dozen or more people but don’t kill four people would not be considered a mass shooting under the more restrictive definition.
"I would submit that sometimes the only difference between a shooting and a murder could be a centimeter, an inch, an unlikely ricochet, whatever," Bueermann, who is now the president of the Police Foundation, which researches law enforcement practices, told the Post. "If we're trying to capture true gun violence in our country, a broader definition [of mass shooting] is probably more useful than a narrow one."
As to the exact claim made by the BBC, a cursory count of the number of rows on Gun Violence Archive as of 8 May 2019 shows that the Highlands Ranch shooting was indeed the 115th mass shooting in the United States in 2019. This is most likely their source for the count of mass shootings.
NOTE FOR COMMENTERS : There seems to be an argument in the comments about whether or not this definition is valid or about the tone of this answer. I am making no claims as to whether or not this definition is accurate or valid, just that the BBC is using this definition, and this definition is not agreed upon by everyone when counting the number of mass shootings.
The BBC is a European organization. For them, as for most of the world, a "mass shooting" is any incident in which multiple people are shot. 4 or more is a frequently used number for "multiple". The rarity of these incidents (outside the US) means that other qualifying circumstances are unimportant.
Based on this definition the cited incident was indeed the 115th mass shooting in the US in 2019, to an accuracy of one or two. This is backed up by data from the Gun Violence Archives, which tracks shooting incidents in the US.
US sources often try to reduce the count of "mass shootings", for example by including only those where 4 were killed rather than just shot, or exclude incidents in domestic settings. Non-US sources have no reason to do that since the numbers of incidents for the UK and other peaceful developed countries are so low that there is no need to distinguish them.
This claim seems to come from a compendium of definitions for mass shooting. The BBC could just be sourcing it directly from this Wikipedia entry, it's not really clear what the article is referencing when it comes to the number of mass shootings so far in 2019.
In the Wikipedia entry, they give 6 different definitions for mass shooting, and include an incident in the list if the incident matches "at least two" of those definitions. The definitions are listed next to which other publication uses it:
There are many definitions of a mass shooting:
Mass Shooting Tracker: 4+ shot in one incident, at one location, at roughly the same time.
Gun Violence Archive: 4+ shot in one incident, excluding the perpetrator(s), at one location, at roughly the same time.
Vox: 4+ shot in one incident, excluding the perpetrator(s), at one location, at roughly the same time.
USA Today: 4+ shot and killed in one incident, at one location, at roughly the same time (same as the FBI's "mass killing" definition).
Mother Jones: 3+ shot and killed in one incident, excluding the perpetrator(s), at a public place, excluding gang-related killings.
The Washington Post: 4+ shot and killed in one incident, excluding the perpetrator(s), at a public place, excluding gang-related killings.
Only incidents considered mass shootings by at least two of the above definitions are listed.
Underneath the list is a table of statistics which states the total number of "events" is 115. I think it is likely that Wikipedia is where the BBC is getting the number from, because of how they qualify the claim in the article itself:
This is believed to be the 115th mass shooting in the US in 2019.
Emphasis added
I did not count the number of rows in the table to see if the number matches, or investigate any of the incidents to see if they do match at least two of the definitions given above.
