GRAB THEM ALL:

If less policing alone led to increased violence, we would have expected to see an uptick in March and April after this clear change. But there was no observable increase in gun violence in these cities at that time.

Police activity dropped again after Derek Chauvin murdered George Floyd in late May 2020, this time with an accompanying surge in shootings in many cities. Cities generally saw stops and arrests increase over the last few months of 2020 -- though still below pre-pandemic levels -- with the elevated level of violence remaining.

While the volume of stops and arrests fell dramatically in March and April in all 10 cities, police in every city were more likely to find a firearm when they made stops and arrests. In Chicago, for example, police stops decreased nearly 70 percent between January and May 2020, but officers actually found 83 percent more firearms in May than in January.

Jens Ludwig, director of the University of Chicago Crime Lab, analyzed stops in Chicago and concluded that "unless the police have become dramatically better at figuring out who is illegally carrying a gun (and so have become better at figuring out who to stop), the implication is that lots more people are carrying guns illegally in Chicago."

The same pattern was seen across numerous cities with available data. There were 34 percent fewer arrest charges in Los Angeles in April and May 2020 compared to April and May 2019, but charges for weapons possession were up. The problem was not confined just to big cities, either. In Tucson, Arizona, for example, there were 39 percent fewer arrests in April and May 2020 compared to a year earlier but 29 percent more arrests for weapons or firearms possession.

Chart: The share of arrests finding weapons jumped as the pandemic began

Data analysis by Jeff Asher and Rob Arthur

The share of stops or arrests that resulted in a firearm being found increased in every city. In Washington, DC, the share of all arrests that were weapons violations went from 5 percent in January to March 2020, to 7 percent in April and 9 percent in May. The share of arrests for weapons possession went from 1 percent between January and March 2020 in Charleston, South Carolina, to 4 percent between April and December.

Almost every city followed the same pattern: a dramatic jump in the share of arrests or stops with a firearm in April and May, a decline in June, and a return to the earlier elevated levels for the remainder of the year.

The implication of this trend is that -- assuming police did not suddenly become substantially better at identifying who has an illegal gun -- firearm carrying increased at the beginning of the pandemic, well before the protests, and persisted at that level for the remainder of the year.

It is possible that in the midst of the pandemic, police started engaging in better-targeted stops that were more likely to yield arrests. But finding other kinds of contraband, like drugs, did not become more frequent, only guns.

Data on investigatory stops -- defined as stops "based upon reasonable suspicion that the person has committed, is committing, or is about to commit a crime" -- in Chicago is instructive and suggests more firearms were found because more were being carried, rather than a change in policing strategy.

The share of searches in investigative stops that found drugs just before Covid-19 lockdowns was virtually unchanged after Covid-19, going from 20.9 percent between October 2019 and March 2020 to 20.7 percent between April and September 2020. The demographics of searches did not change much, either, with Black people making up 74.3 percent of people searched in stops from October 2019 to March 2020 and 76.1 percent from April through December. But CPD officers found firearms in 11.5 percent of searches from April to September, compared to 3.7 percent of searches in the six months prior.

Since all cities with data had an increase in the share of stops or arrests with a gun at around the same time, no one change in departmental or prosecutorial policy can explain why.

Investigative stops and arrests show an increase in firearm carrying beginning in March or April, shortly after background checks surged to unprecedented levels nationally. More firearms could have contributed to the historic rise in murders in 2020 by turning less dangerous crimes into potentially lethal encounters.

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