Mass Shootings and Assault Weapons

UPDATE: This post has been updated to include the Tree of Life Synagogue shooting that occurred on October 27th, 2018. 

The death toll in the Marjory Stoneman Douglas High School shooting in Parkland makes it one of the deadliest gun massacres in U.S. history, and it was the deadliest school shooting since 20 first graders and six educators were gunned down inside Sandy Hook Elementary School. After the Parkland shooting, it emerged that the perpetrator purchased his AR-15 assault rifle legally. That weapon and others like it were once banned under U.S. law and there are growing calls for a reintroduction of that legislation.

The AR-15 is a civilian version of the military grade M4 and M16 type of rifles that are designed to deliver relatively small sized rounds at high velocity in order to inflict devastating and lethal wounds. “Routine handgun gunshot injuries leave entry and exit wounds and linear tracks through the victim’s body that are roughly the size of the bullet….The bullets fired by an AR-15 are different: They travel at a higher velocity and are far more lethal than routine bullets fired from a handgun. The damage they cause is a function of the energy they impart as they pass through the body. A typical AR-15 bullet leaves the barrel traveling almost three times faster than—and imparting more than three times the energy of—a typical 9mm bullet from a handgun.” (from “What I Saw Treating the Victims From Parkland Should Change the Debate on Guns”)

In his book “Rampage Nation” Louis Klarevas of the University of Massachusetts at Boston notes that gun massacres (defined as a shooting incident in which six or more people are shot and killed) fell 37 percent during the period the federal assault weapons ban was in place between 1994 and 2004, and that in the ten years after it lapsed, they went up an alarming 183 percent.


Below are the deadliest mass shootings in modern US History. Note that only two (Columbine and Atlanta, both in 1999) occurred during the 10 year period (1994 – 2004) the assault weapons ban was in place.
Shootings where a semi-automatic rifle was used are highlighted.

Incident Year Number Killed Number Injured
Tree of Life Synagogue Shooting 2018 11 6
Santa Fe High School shooting 2018 10 14
Stoneman Douglas High School shooting 2018 17 17
Las Vegas shooting 2017 59 (incl. the perp.) 851 (422 from gunfire)
Sutherland Springs church shooting 2017 27 (incl. the perp.) 20
Orlando nightclub shooting  2016 50 (incl. the perp.) 53
San Bernardino attack 2015 16 (incl. both perps.) 24
Umpqua Community College shooting 2015 10 (incl. the perp.) 8
Washington Navy Yard shooting 2013 13 (incl. the perp.) 8
Aurora shooting 2012 12 70
Sandy Hook Elementary School shooting 2012 28 (incl. the perp.) 2
Binghamton shootings 2009 14 (incl the perp.) 4
Fort Hood shooting 2009 14 33 (incl the perp)
Geneva County massacre 2009 11 (incl. the perp.) 6
Virginia Tech shooting 2007 33 (incl. the perp.) 23
Red Lake shootings 2005 10 (incl. the perp.) 5
Atlanta shootings 1999 10 (incl. the perp.) 13
Columbine High School massacre 1999 15 (inc. both perps.) 24
Luby’s shooting 1991 24 (incl. the perp.) 27
GMAC shootings 1990 10 (incl. the perp.) 6
Edmond post office shooting 1986 15 (incl. the perp.) 6
Palm Sunday massacre 1984 10 0
San Ysidro McDonald’s massacre 1984 23 (inc. the perp.) 19
Wah Mee massacre 1983 13 1
Wilkes-Barre shootings 1982 13 1
Easter Sunday massacre 1975 11 0
University of Texas tower shooting 1966 18 (incl. the perp) 31
Camden shootings 1949 13 0


Additional reading:

With AR-15s, Mass Shooters Attack With the Rifle Firepower Typically Used by Infantry Troops – New York Times

Why the AR-15 keeps appearing at America’s deadliest mass shootings – USA Today

Is It Time to Bring Back the Assault Weapons Ban? – Statista

Assault guns are not just about mass shootings — they’re also a big factor in attacks on police and other crimes – LA Times