Ranked: Countries With the Most Serial KillersKey Takeaways:The United States has 3,803 documented serial killers since 1900, accounting for 62.9% of the total in the dataset.No other country has 200 documented cases, with England (188) and Russia (172) ranking a distant second and third.Known U.S. serial killers have declined sharply: fewer than 50 were active in the 2010s, compared with nearly 300 in the 1970s.The United States stands out dramatically in the 2026 Radford/FGCU Report on Serial Killer Statistics, which compiles identified serial killers by country.These figures reflect documented cases rather than the true prevalence of serial murder. Differences in law enforcement, case classification, record accessibility, and reporting can significantly affect country totals.The U.S. Dominates Documented CasesThe following table shows countries with at least 10 identified serial killers, excluding offenders whose crimes spanned multiple countries. Radford University defines a serial killer as an offender who commits the unlawful killing of two or more victims in separate events.RankCountryIdentified Serial Killers% of Serial Killers1 United States3,80362.912 England1883.113 Russia1722.854 Australia1532.535 Japan1452.406 India1352.237 South Africa1322.188 Canada1302.159 Germany1051.7410 Italy1021.6911 France971.6012 Mexico731.2113 China691.1414 Brazil460.7615 Poland310.5116 Spain310.5117 Hungary300.5018 Austria250.4119 Colombia240.4020 Netherlands210.3521 Belgium190.3122 Czech Republic180.3023 Argentina180.3024 Sweden160.2625 Türkiye160.2626 Thailand150.2527 Scotland140.2328 Nigeria140.2329 Pakistan140.2330 Greece130.2231 Kenya130.2232 Iran130.2233 Ukraine120.2034 South Korea110.18The gap between first and second place is enormous. The U.S. has 3,803 identified serial killers, more than 20 times England’s total of 188. Russia ranks third with 172, followed by Australia (153) and Japan (145).This disparity does not necessarily mean Americans are inherently more likely to become serial killers. Radford University researcher Mike Aamodt has argued that U.S. cases are easier to identify and document because police, prison, and public records are relatively accessible.As a result, these figures are best understood as a ranking of identified cases, not the true prevalence of serial murder. Countries with less accessible records may have cases that were never identified or documented. Similar measurement challenges affect comparisons of the world’s most dangerous countries, where results depend heavily on which crimes are measured and recorded.Why Have Serial Killings Declined?Serial killing in the U.S. peaked decades ago. Research cited by Northeastern University estimates that nearly 300 known serial killers were active during the 1970s, compared with fewer than 50 during the 2010s, a decline of more than 80%.Several factors may explain the decline. DNA evidence, surveillance cameras, and improved information sharing between police departments have made it considerably harder for repeat offenders to remain unidentified across multiple crimes.Changing social behavior may have played a role as well. Hitchhiking and other situations that left people isolated with strangers were more common during the peak decades. The decline also occurred alongside broader changes in violent crime, though homicide rates across regions show that lethal violence remains highly uneven around the world.Other explanations remain debated. Author Caroline Fraser has explored environmental lead exposure as one potential contributor to the earlier surge in violent behavior, while criminologist James Alan Fox has emphasized factors including demographics, improved policing, and advances in forensics. No single theory fully explains the rise and subsequent decline.Learn More on the Voronoi AppFor another data-driven look at mortality, see The Top Causes of Death in the United States on the Voronoi app.