FEMALE SERIAL KILLERS: More Common Than You Think: “The details of the women’s crimes differed notably from those committed by men. Nearly all of the women in Harrison’s study had killed people whom they knew, often targeting their husbands and children. Male serial killers, in contrast, appear much more likely to kill strangers. Whereas the most common motive for male serial killers is sex, female murderers were most often driven by money; almost half of the women in Harrison’s sample killed for financial gain. And poison was by far their preferred method; male murderers are most likely to shoot, strangle, or stab their victims.”