More mass shootings happen on the weekends

Andrey Kamenov, Ph.D. Probability and Statistics

One of the most notorious mass shootings in recent years happened in San Bernardino, California on Wednesday, December 2, 2015. If we look at other reports, however, six out of 10 gun violence incidents with the highest number of victims took place on Saturday or Sunday. Is it true that such catastrophic events are more likely to happen during weekends?

Below is a chart showing the total number of reports from the Gun Violence Archive website with at least four victims (injured or killed) grouped by day of the week.

Mass shootings by day of week

It’s pretty obvious that the number of mass shootings happening on weekends is much higher. Our statistical analysis confirms this – the difference is extremely significant.

Interestingly enough, while 53 percent of all incidents occurred on Saturdays or Sundays, they account for 44 percent of all victim deaths, so weekend incidents seem to be less violent on average.

On the other hand, the distribution of incidents that happened during weekdays seems more uniform. And again, relatively high p-values in our tests imply that the data is indeed consistent with uniform distribution.

Here’s the map showing the locations of the last 500 events.

Mass shootings in the U.S.

Outside of some local patterns (for example, all five reported events happened on weekdays in Arizona), there’s actually no significant difference between densely-populated metropolitan areas and rural counties.

Source(s):

Discuss this article on our forum with over 1,900,000 registered members.

About Andrey Kamenov

Andrey Kamenov, Ph.D. Probability and Statistics

Andrey Kamenov is a data scientist working for Advameg Inc. His background includes teaching statistics, stochastic processes and financial mathematics in Moscow State University and working for a hedge fund. His academic interests range from statistical data analysis to optimal stopping theory. Andrey also enjoys his hobbies of photography, reading and powerlifting.

Other posts by Andrey Kamenov:

Leave a Reply

Your email address will not be published. Required fields are marked *