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always nice

An Overview On Mass Shootings

There is not yet a standard definition of the term mass shooting. The definition of mass shooting used by Stanford is three or more shooting victims (dead or injured), not including the shooter. The shooting must not be identifiably gang, drug, or organized crime related.

Only episodes with more than four victims were considered. From 1966, the year of the first recognized mass shooting, to 2017, a total of 358 events occurred.

The most infamous events

While 358 events occurred from the year the FBI started recording these events, a few of them marked the collective conscience of the country, becoming some of the most recognized tragedies of the last decades.

Seventeen of them were either the most brutal, the most shocking or the most unexpected events, and almost anyone can recognize at least one of them from this list. The Las Vegas Strip Shooting was the deadliest shooting, while the Orlando Pulse Nightclub shooting was the most brutal attack against the LGBTQ+ community in recent history.

Each figure describes one of the 16 most famous event. The size of the circle represents the amount of victims, the color the perpetrator’s mental state and the black lines the number of weapons used.

Hover or touch the figures to get additional and comprehensive information.

Mental health

mentally ill




one weapon used




State of the perpetrator





Mapping, to understand where incidents occur

What happens when we see where these events took place? Mass shootings happen all over the US. They usually take place in populous areas of the Country, however each event, from the ones that took place in large cities like San Francisco to the ones that took place in the most secluded places, like the one at the West Nickel Mines School in Lancaster, Pennsylvania, hides a complex story of unhappiness, restlessness of regular people that were, apparently, living a normal life.

In the interactive map each dot represents an event and the saturation indicates how much the event is close in time to the present.

Zoom and drag the map, and hover on the circles to get additional information.

The tools used to kill

From 1966 an amount of 299 various weapons including handguns, rifles and shotguns were used to kill. The most abundant arsenal is related to the Las Vegas Strip mass shooting when Stephen Craig Paddock opened fire from the 32nd of an hotel with 23 rifles.

The arsenal used across all mass murders is varied both in size and type of guns, but all of these informations highlight the ongoing and complex discussion about gun control in the US.

Since not all recorded events are complete in their information, a set of 151 events is shown.


Legislations and mass murders, an ongoing struggle

Gun control is one of the most polarizing issues in U.S. society. For nearly a century, legislation and U.S. Supreme Court cases have shaped federal gun policy.

Especially from the assassination of John F. Kennedy on November 22th, 1963 the debate has grown, becoming a widespread topic alla around USA.

All bills, acts and events are placed in a chronological order, both on the X axis and Y axis, and colored by their typology, whether it is a bill, an act or a general event. Down below, a comparison with all the victims, injured and killed, from 1966 to 2018.

Click on the laws, represented by squares on the timeline, to get additional information.

Event type



general event

Casualities in all mass murders

A comprehensive view on each killer and event

When looked all together, mass shootings and their perpetrators share similar patterns in location, gender and race. These events are perpetrated by people of all races, however, they are predominantly men.

While people of all ages perpetrate mass murders, the youngest killers were just 13 and 11 years old: Mitchell Scott Johnson and Andrew Douglas Golden, in 1998, ambushed students and teachers as they left the school in Jonesboro, Arkansas.

In the visualization, single events (always represented by single circles) can be divided into different categories on the vertical axis; and they can be distributed by various numerical values on the horizontal axis.

Click on the buttons to redistribute circles on the graph. Hover or touch the circles to get additional information.

Mental health

mentally ill



not available

The list of mass shootings keeps getting longer. The most famous cases are the ones that mostly arose media attention even if the phenomenon of mass shootings is a daily issue for american people, so much so that introduction of laws and bills have been more and more frequent especially in the last two decades.

For this reason, mass shooting episodes require observation and an information gathering as precise as possible in order to have a clearer and universal vision of the phenomenon.

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