The 20th-century like the previous centuries has seen no end of murders by women with poison as their choice of weapon. And, like the previous centuries the murders have been just as cold and calculating. Why do women prefer to murder with poison? It avoids physical confrontation. It is cleaner than the ugly bloodied scenes of guns or knives. And they believe it is a method that will allow them to get away with murder. Those lucky few, who have managed to survive an attempted murder by these women, have described been poisoned as being equal to being devoured alive. However, the 20th century has also seen murders committed by women with guns, and in the case of Dana Gray, with physical violence. Dana is a rarity among women serial killers, both in her choice of victim and her hands-on method of using her hands, a cord or rope, and an object in which to batter her victim. Aileen Wuornus, was described in the popular press as the first American woman serial killer. This is totally incorrect. American women serial killers existed long before Aileen Wuornos was born. So what leads a woman to commit serial murder? The vast majority of serial murders committed by women in the 20th century, as in earlier centuries, have been committed for money and materialistic gain. Other reasons include a need to overpower, attention seeking behavior and personality disorders to name just a few. In this book, I examine the profiles of twenty-five women serial killers, all of whom acted alone. I have not included mothers who kill their children, as I believe, that is a subject that deserves to be written about entirely separately. Welcome to the world of 20th century women serial killers.