It is at 31.4 years that the average woman multiple murderer kills the first of her 17 victims, whom she usually knows or is related to. The preferred method is poison, usually arsenic. She is more likely to prey on the vulnerable--the very young or the very old--than her male counterpart. Her killing spree lasts five years; when caught, she shows little remorse.This profile of 85 women focuses on those who have killed at least three people, not including...