http://www.bbc.com/news/world-us-canada-34996604按bbc的数据，"A mass shooting is defined as a single shooting incident which
kills or injures four or more people, including the assailant." 所以没有打死，打伤的也算。
我觉得一些媒体是有意或者无意的混淆 mass murder and mass shooting。 这个四人及以上，是从fbi 定义的 mass murder 人数来的。
A mass shooting is an incident involving multiple victims of gun violence.[1] The United States' Congressional Research Service acknowledges that there is not a broadly accepted definition, and defines a "public mass shooting"[2] as one in which four or more people selected indiscriminately, not including the perpetrator, are killed, echoing the FBI definition[3][4] of the term "mass murder". Another unofficial definition of a mass shooting is an event involving the shooting (not necessarily resulting in death) of 10 or more people with no cooling-off period.[5] Related terms include school shooting and massacre. The lack of a single definition can lead to alarmism in the news media, with some reports conflating categories of crimes.[6]
https://www.thetrace.org/2015/12/gun-violence-stats-2015/Generally, there are three terms you'll see to describe a perpetrator of this type of gun violence: mass murderer, spree killer, or serial killer. An FBI crime classification report from 2005 identifies an individual as a mass murderer if he kills four or more people in a single incident (not including himself), typically in a single location. (The baseline of four fatalities is key—more on that just below.)
我不同意的是把走火和自杀的和mass murder/ shooting 一起说事。这两类和汽车的交通事故引起的意外伤亡类似。
而且奥兰多就是一个极端分子计划了很久的事儿。这个和欧洲的恐怖袭击类似。
国会不是不可能通过法案，而是两边都要夹带私货，借机攻击对手。所以说那帮政客最无耻，这个时候还不愿意妥协。