Were mass shootings significantly less frequent before the 2000s?
This fact-check may be outdated. Consider refreshing it to get the most current information.
Executive summary
Available databases and government-funded research show mass shootings in the U.S. have become more common since mid‑20th century, with multiple analyses reporting that “more than half” of public mass shootings occurred after 2000 (NIJ/Justice Dept.; Violence Project) and several datasets finding steady increases from the 1970s–2000s (Wikipedia summary; RAND) [1] [2] [3] [4].
1. Definitions drive the headline — no single agreed count
Scholars and outlets use different thresholds (fatalities vs. people shot, public vs. private, exclusion of gang/drug killings), and those choices change whether the data show big increases; the Gun Violence Archive, Mother Jones, the FBI and academic projects all use differing criteria, producing divergent time‑series and thus different answers to whether mass shootings were “significantly less frequent” before the 2000s [5] [6] [7] [2].
2. Multiple datasets and reviews find increases since the 1970s–1980s
Analyses cited in encyclopedic and peer‑reviewed summaries report a rise in mass shootings over recent decades: a 2018 PLOS One study of 100 Mother Jones cases concluded steady increases from 1982–2018; broader reviews cite an upward trend from 1970 to 2015 linked to social‑capital decline; and a 2014–2022 clinical study noted “more than half occurring since the year 2000” [3] [6] [2].
3. Government‑funded database: concentration after 2000
The National Institute of Justice–supported Violence Project database and the Justice Department’s summary report state that more than half of identified public mass shooters occurred after 2000, with about 20% in the last five years of that study window; the DOJ also reported that in the 1970s mass shootings averaged roughly eight deaths per year, indicating both growth in frequency and in fatalities over time in that dataset [1] [8].
4. RAND and researchers caution about interpretation
RAND’s synthesis emphasizes that changing offender types (school shootings in the 1960s–70s, workplace shootings rising in the 1980s–2000s) and the lack of a standard definition mean trends are sensitive to methodological choices; RAND notes that different definitions produce different findings on prevalence and trend direction [4].
5. Media attention and measurement have both intensified
Researchers highlight that the media’s use of the term “mass shooting” has increased significantly in recent decades, which amplifies public perception and complicates simple frequency comparisons across eras because reporting effort and public consciousness are not constant over time [4].
6. Alternative measures show nuance: events vs. fatalities vs. types
Some sources show that while event counts rose, the composition shifted: types of targets, offender motivations and whether shootings occurred in public or private settings changed across decades — meaning “less frequent before 2000” is partly true for certain subtypes (for example, a preponderance of school shootings in earlier decades) but not uniformly true for all definitions of mass shooting [4] [3].
7. Data limitations and contested causation
Researchers point to associations (e.g., residential instability, poverty, reduced civic engagement) correlated with higher mass‑shooting rates but caution that causal claims are difficult; studies of policy effects such as the 1994–2004 Federal Assault Weapons Ban yielded mixed and inconclusive results in subsequent reviews like RAND’s 2023 assessment [3] [4].
8. What the best current reporting supports — a qualified conclusion
Taken together, multiple independent databases and government‑funded research support the conclusion that mass shootings became more common after 1980 and especially after 2000 under many commonly used definitions; however, the exact magnitude of the increase depends on which dataset and definition you choose, and scholars such as RAND warn about overinterpreting raw counts without attention to definitional and reporting shifts [1] [2] [4].
9. Questions the sources don’t settle
Available sources do not mention a single, authoritative time‑series that accounts for changing media coverage, definition drift, emergency‑care improvements, and classification of motive simultaneously; they also do not provide an undisputed causal explanation tying the rise uniquely to one factor [4] [1].
If you want, I can: (a) compare year‑by‑year counts from two specific databases (Mother Jones vs. Gun Violence Archive) to show how definitions change trend lines, or (b) summarize the Violence Project’s psychosocial profile findings to explain shooter commonalities cited in the DOJ/NIJ reporting [6] [1].