Serial killers have been declining in number since they peaked in the 1990s 1930, as shown by the main database of serial killers in the world.
In the decade of 1990, Radford University professor of forensic psychology Michael G. Aamodt began giving his class an assignment: create a profile of serial killers, including a timeline of their murders, their life history, basic demographic information, and information about their crimes.
At first, the projects were kept in a drawer and added to the class website years later. Finally, the information was transferred to a database and became its own project to update and maintain the most complete database on serial killers over the years.
Using the FBI definition of serial killers (people who unlawfully killed two or more victims in separate events), researchers at Radford University and Florida Gulf Coast University have documented killers from around the world, with some rather interesting finds.
The United States, the country with the most serial killers
For example, the United States is the country with the most registered serial killers, with 3,613 from the year 1900. That’s the 67 percent of the world’s serial killers, for a country with 4.35% of world population. The next closest is England, with 123. Japan (137), South Africa (123), India (121) and Canada (119) are the only other countries where there have been more than 67 serial killers identified by the database.
Since the beginning of the data in 1900, approximately 11 percent of serial killers have been women, and the percentage of female serial killers has decreased over the years compared to men.
Serial killers
Before the decade of 1900, about a third of serial killers were women, down to about six percent from 1980. Female serial killers were more likely to use poison than male serial killers, and to kill for financial gain as a primary motive.
Meanwhile, male serial killers were more likely to kill for their own enjoyment and more likely to do so by shooting or strangling their victims. Victims of female serial killers are more likely to be family members, rather than male serial killers who tend to kill non-family members.
Breaking down the crimes further, the database has some other pretty grim facts. This includes information on whether the serial killer ate his victims (about 1.8% of male serial killers did, compared to 1.3% of female serial killers), whether necrophilia occurred (3.4% of male serial killers did this, compared to 0.4% of female serial killers).