From CNN:

Mass Shootings in the US Fast Facts
By Daniel Wolfe and John Murphy-Teixidor, CNN

Last updated: Sept. 16, 2021

Here are the ten most recent mass shootings:

Man, those Trump-voting rural rednecks in Baltimore, Cleveland, Milwaukee etc. are out of control with their AR-15s!

Also from CNN:

Mass shootings in the US increased during the coronavirus pandemic, study finds
By Lauren Mascarenhas, CNN

Updated 3:18 PM ET, Thu September 16, 2021

(CNN)Mass shootings in the United States increased during the coronavirus pandemic, and even doubled in July 2020 compared to a year earlier, according to research published in the journal JAMA Open Network Thursday.

The team observed an increase in mass shootings after May 2020, compared to trends in previous years. There were 88 such shootings in July 2020, 42 in July 2019 and 45 in July 2018, the team noted.

City police departments are also reporting an increase in gun violence during the pandemic. In Chicago, shooting incidents are up 64% so far this year compared with the same period two years ago.
Last year, there were 611 mass shootings around the country, compared with 417 a year earlier, according to Gun Violence Archives. This year there have been 498 mass shootings, 34 just in September so far.

From the Journal of the American Medical Association:

Mass Shootings in the US During the COVID-19 Pandemic

Research Letter / Health Policy
September 16, 2021

Pablo A. Peña, PhD1; Anupam Jena, MD, PhD2,3,4

1Kenneth C. Griffin Department of Economics, University of Chicago, Chicago, Illinois
2Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
3Department of Medicine, Massachusetts General Hospital, Boston
4National Bureau of Economic Research, Cambridge, Massachusetts

Introduction
Mass shootings are rare events with causes that are not well understood, particularly, the extent to which they are responses to social and economic circumstances. The COVID-19 pandemic imposed sudden and additional psychological and financial strains across society through fear of death, social isolation, economic hardship, and general uncertainty. …

This cross-sectional study analyzed changes in mass shootings during the COVID-19 pandemic by examining publicly available information about mass shootings in the US between January 1, 2014, and June 30, 2021, from the Gun Violence Archive, a repository of gun violence incidents collected from over 7500 law enforcement, media, government, and commercial sources. In the data, mass shootings are defined as shootings in which 4 or more people were killed or injured, not counting the perpetrator.

… We plotted 28-day moving means of the count of mass shootings in each year between 2014 and 2020, with partial data from January to June 2021.

In other words, if mass shootings exploded around, say, to pick a date at random, May 25, 2020, then the black line on the graph above would rise from May 11, 2020.

An increase in mass shootings was observed from May 2020 onward compared with the trends in the years prior (Figure). For example, 88 shootings occurred in July 2020, 42 shootings occurred in July 2019, and 45 shootings occurred in July 2018.

In an event study analysis, we estimated that following April 16, 2020

For unexplained reasons, they decided the pandemic started on April 16, 2020 rather than about four weeks earlier.

, there were a mean of 0.78 (95% CI, 0.52-1.04) additional daily mass shootings, 0.49 (95% CI, 0.07-0.92) additional people killed daily, and 3.40 (95% CI, 2.07-4.72) additional people injured daily in mass shootings. …

Overall, the estimates suggest that over the 15 months analyzed there were 343 mass shootings above expected, involving an additional 217 people killed and 1498 people injured. Findings were robust to analyses that modeled alternative start dates (Table)

They modeled four start dates: March 16, 2020, April 1, 2020, April 16, 2020, and May 1, 2020, with the the number of incremental mass shootings going up with each additional half a month.

Why did they stop at May 1, 2020 rather than, say, the day the Racial Reckoning began, May 25, 2020? And why not use actual mass shootings rather than a four week moving average?

Don’t mention the Racial Reckoning!