The vast majority of murders in the United States are committed by men, and that includes serial murders.; approximately 17 percent of all serial homicides in the U.S. are committed by women. Interestingly, only 10 percent of total murders in the U.S. are committed by women indicating that, compared to men, women represent a larger percentage of serial murders than of any other kind of homicide in the U.S. So, statistically speaking, there are more women in the “serial killer” group than there are in the “killed someone in a bar fight” group or “I beat my spouse to death” cohort. Given the fact that female serial killers tend to get away with their crimes longer, and to kill more victims, suggests that this is a group that deserves some much-needed attention – and detection.

https://www.psychologytoday.com/us/blog/the-human-equation/201803/five-myths-about-female-serial-killers