Visualizing the 2020 Spike in Murders Across the US

In most ways, 2020 ended up being a pretty “quiet” year. Many workers stayed home to work virtually, international travel ground to a halt, and most Americans limited their social contact to a much smaller circle than normal to reduce the spread of COVID-19.

Influenza Spread Dries Up

That reduction of activity and contact is stark when viewed in the context of the spread of the flu - look at the shockingly low levels of influenza transmission recorded in 2020 and 2021, as charted by Scientific American:

US Flu Positivity Rates from Scientific American

Murders Rise

However, despite the many indicators saying “things are chill”, one extremely important indicator did something unexpected. While crime in total dropped in 2020, just like the flu, the number of murders committed actually increased significantly year on year, with the the 30 largest cities in the US seeing an over 30% rise in the murder rate.

I would like to credit an anonymous hero for putting together the 2020 murder figures before official release of the FBI statistics (which are still only through 2019) - if you peek at the data they’ve shared, publicly available in a Google Sheet, you can see the source for each city’s figures saved as a reference.

Given the richness of the dataset, as well as the incredibly important trend (we didn’t see anyone but also we decided to shoot everyone else??), I decided to put together some visualizations of the trends which might better illustrate these developments than a simple table.

Absolute Change in Quantity of Murders by City

When slicing the volume of murders by city, the standout trait is just how consistent the trend is - 27 of the 30 largest cities observed an increase in murders, with only Baltimore, Albuquerque, and Oklahoma City recording deceases in 2020 compared to 2019.

Total Murders per US City in 2019 and 2020

The chart above shows that Chicago, Philadelphia, and New York recorded the largest absolute number of murders in 2020, as well as largest absolute increases in murders year on year. However, that feels like an imperfect way of looking at this - those are three of the largest cities in the US, so it makes sense that they have the most murders.

To solve this, we’ll add another dimension to this data to quantify the number of murders relative to the population, so we can arrive at a murder rate, commonly expressed as a # per 100,000 residents.

With that done, we can then visualize the changes in each city as what I’m calling a “scatterpath” chart, which has an arrow pointing from the 2019 to 2020 data for each city and simultaneously visualizes the change in both absolute volume of murders and murder rate.

Total Murders and Murder Rate per US City in 2019 and 2020

In this context, Chicago’s numbers are less troubling - Murders clearly rose significantly, but the city has an overall murder rate which is more in the middle of the pack. However, cities like Baltimore, New Orleans, and Detroit really pop on behalf of their high rates.

We may never know what drove this surge - every interview with criminologists I’ve read has been inconclusive as to the root causes - but it’s certainly a notable fact from a notable year, and as such I found it to be worth sharing.

In the future, perhaps we can agree on a bit less murdering, and a bit more of the flu?