How did mass shooting rates change year-by-year during Trump's presidency (2017–2020)?
Executive summary
Mass-shooting counts reported by major trackers generally rose across 2017–2019 and then jumped sharply in 2020, but the magnitude and year-to-year picture depend heavily on which database and definition are used; the Gun Violence Archive (GVA) — commonly cited in recent research — shows a rise from hundreds of incidents in 2017–2019 to roughly a 30%–50% increase in 2020 (2019 ≈ 410; 2020 ≈ 602) [1]. At the same time, narrower definitions (for example counting only public incidents with multiple fatalities) yield different year-to-year counts and highlight how single catastrophic events (such as Las Vegas in 2017) can distort casualty totals even when incident counts move more slowly [2] [3].
1. Rising baseline through 2017–2019: more incidents, more eyes on the problem
Multiple analyses report an upward trend in mass-shooting incidents through the late 2010s: studies using the Gun Violence Archive and similar datasets recorded hundreds of mass-shooting incidents annually, with 2017–2019 showing steady increases in frequency and fatalities before 2020 [1] [4]. Researchers note that media attention and improved real-time tracking made many of these incidents more visible, but even after accounting for reporting, the trend lines from 2013–2019 point upward, producing the “worsening epidemic” framing used in surgical and public-health literature [5] [4].
2. The 2020 jump: pandemic, social upheaval, or data artifact?
Several peer-reviewed studies and GVA-derived analyses identify a pronounced jump between 2019 and 2020 — for example one statistical review finds a 31.9% single-year increase from 410 incidents in 2019 to 602 in 2020 — and note that 2020 and 2021 exceeded extrapolated predictions from prior years [1] [5]. Authors have proposed multiple explanations for the 2020 spike, including pandemic-driven social stressors, changes in routine activities, and localized surges in violence; however, the literature also cautions that definitional choices and database coverage substantially influence the measured increase [4] [2].
3. Definitions drive the story: incidents vs. fatalities, public vs. all settings
Counting rules matter: GVA defines a mass shooting as four or more people shot (excluding the shooter) and therefore reports many more incidents than conservative datasets that count only events with multiple deaths or only public mass killings [6] [7]. RAND and NIJ analyses emphasize that casualty totals can be dominated by single catastrophic events (Las Vegas, 2017) so that year-to-year death counts are more volatile than incident counts — and that different research questions (policy targeting deaths vs. preventing all multi-victim shootings) require different datasets and yield different year-to-year narratives [2] [3].
4. 2017’s mixed picture: incident counts versus deadliest events
2017 illustrates the methodological hazard: although some databases record several hundred mass-shooting incidents that year, national casualty figures for mass public shootings are heavily influenced by the October 2017 Las Vegas attack, which accounted for more than half of that year’s mass-public-shooting casualties in some analyses; consequently, whether 2017 looks better or worse than adjacent years depends on whether the focus is incident frequency or total deaths and injuries [2] [3].
5. A cautious bottom line for 2017–2020
Across the available reporting, the consistent pattern is a rising frequency of mass-shooting incidents from 2017 through 2019 and a clear, documented spike in 2020 according to broad-coverage trackers like GVA and multiple peer-reviewed analyses [1] [5] [4]. That conclusion must be prefaced: different definitions yield different annual counts, single catastrophic events can skew casualty totals, and some subcategories (notably school shootings) show unique deviations in 2020 tied to pandemic school closures (school shootings fell in 2020 even as overall incidents rose) [8] [5].
6. What the data cannot settle without more work
Existing sources converge on the direction — upward through 2019 with a 2020 spike — but cannot fully disentangle the causes at scale; researchers explicitly warn about base-rate issues, database discrepancies, and the limits of predicting rare events, and they recommend care when translating incident-count trends into policy prescriptions [1] [2] [4]. For any precise year-to-year comparison, the choice of dataset and definition must be stated up front, because the narrative changes markedly depending on those choices [7] [1].