Contrary to popular mythology, not all serial killers are white. Serial killers span all racial and ethnic groups in the U.S. The racial diversity of serial killers generally mirrors that of the overall U.S. population. There are well documented cases of African-American, Latino and Asian-American serial killers.
African-Americans comprise the largest racial minority group among serial killers, representing approximately 20 percent of the total. Significantly, however, only white, and normally male, serial killers such as Ted Bundy become popular culture icons.
Although they are not household names like their infamous white counterparts, examples of prolific racial minority serial killers are Coral Eugene Watts, a black man from Michigan, known as the “Sunday Morning Slasher,” who murdered at least seventeen women in Michigan and Texas, Anthony Edward Sowell, a black man known as the “Cleveland Strangler” who kidnapped, raped and murdered eleven women in Ohio; and Rafael Resendez-Ramirez, a Mexican national known as the “Railroad Killer,” who killed as many as fifteen men and women in Kentucky, Texas, and Illinois.
The myth that all serial killers are white is related to another commonly held myth that most murders, including serial murders, are inter-racial in nature—that is, the perpetrator and victim are from different races. The reality is that homicides of all types in the U.S. are generally intra-racial in nature.
https://www.psychologytoday.com/us/blog/wicked-deeds/201412/serial-killer-myth-6-they-are-all-white
Female:
We don’t know for sure; according to Mike Aamodt, an impressive serial killer statistician out of Radford University, there have been 514 female serial killers since 1910. Of course, we only know about the ones who are caught. Given the sneaky ways most female serial killers operate, I’m sure this is an underestimate.
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