The world’s largest serial murderer database has revealed that the number of serial killers has been declining ever since it peaked in the 1980s.
Michael G. Aamodt, a professor of forensic psychology at Radford University, started giving his students a project in the 1990s that involved constructing a profile of the serial killers that included details about their crimes, a timeline of their killings, and facts about their lives. The projects were initially kept in a drawer and later published on the class website. The material was eventually transferred to a database, and updating and maintaining the most complete database on serial killers throughout time became a mission unto itself.
Researchers from Radford University and Florida Gulf Coast University have documented murders from all over the world using the FBI definition of serial killers (those who unlawfully killed two or more victims in separate incidents), and their research has produced some rather fascinating findings.
For instance, 3,613 serial killers have been identified in the US since 1900, making it the nation with the highest number. For a nation with 4.35 percent of the global population, it equates to 67 percent of all serial killers. England comes in second place with 167. The only other nations with more than 100 serial killers identified by the database are Japan (137), South Africa (123), India (121), and Canada (119).
Approximately 11% of serial killers have been female from the data’s inception in 1900, yet this number has decreased over time compared to male serial killers. Before the 1930s, around a third of serial killers were female; after 1980, that percentage decreased to about 6%. In comparison to male serial killers, female killers were more likely to use poison and to kill primarily for financial gain. In contrast, male serial killers tended to kill for their own amusement and were more likely to shoot or strangle their victims. Compared to male serial killers, who typically target strangers, victims of female killers are more likely to be relatives.
The database has some more, really bleak details that break down the crimes further. This information includes details about the serial killer’s behavior, such as whether they consumed the flesh of their victims (about 1.8 percent of male serial killers did this, compared to 1.3 percent of female serial killers), engaged in necrophilia (3.4 percent of male serial killers did this, compared to 0.4 percent of female serial killers), and drank the blood of their victims (0.7 percent of male serial killers and 0.4 percent of female serial killers).
The drop in serial killings in the United States since their absolute high in the 1980s—404 victims in 1987 alone—is one peculiar finding of the data. There were 150 serial killers who killed two or more victims in the 1980s, and 104 of them killed three or more.
Since then, the number of serial killers has drastically decreased. In the 1990s, there were 138 killers who killed two or more victims and 89 who killed three or more. Just 43 serial killers had killed two or more victims in those years, and 23 had killed three or more (2010-2018 was the last year having complete data in the database at the time of the final update).
The researchers attribute this drop to a number of things. A contributing factor to the decline may be law enforcement’s increased ability to spot criminal activity, such as insurance fraud, so that financial-motivated serial killers are either apprehended before they meet the criteria for being classified as serial killers or dissuaded from committing murders for financial gain altogether.
Additionally, opportunities for experienced serial killers and would-be serial killers looking for their first victim have decreased.
The team writes in the 2020 report that “fewer prospective serial killers have returned to the streets as a result of stricter parole laws.” “16.8% of the serial killers in our database who committed another murder after being released from jail for a prior killing in the United States since 1950. The correlation between longer prison sentences and a decline in the frequency of serial killers is supported by this statistic as well as the fact that 79% of American serial killers served time in jail or prison prior to committing their first murder.”
Since hitchhiking has decreased, so have the opportunities. “There are fewer high-risk targets available for serial murders. In other words, fewer people are walking to school, volunteering rides to strangers, and hitchhiking “The group went on. From 1980 to 1999 to 2000 to 2017, “among of the largest decreases in serial murderer victim types were related to hitchhiking, abductions from shopping centers, and disabled motorists or good Samaritans.”