Having discussed women who kill their children in another book (From Mommy to Monster), I feel it only fair to look at the other side. Fathers who kill their children, and frequently their wives as well, are known as "Family Annihilators" to criminal psychologists or psychiatrists, and to law enforcement. They are not mentally ill, but coldly calculating, and often spend months planning their crimes. Because they often kill themselves too, these crimes don't always make the news in media-friendly trials, but in the United States, there are 10 murder-suicides each week. Fathers who kill their children do so for many reasons. While some are truly tragic cases, others are either overly egotistic in their sense of ownership of their families or clearly just eliminating burdens to get a new lease on life. The major factors leading men to kill their families include impending divorce, male sexual jealousy, an obsession with control, and possessiveness, according to criminal psychology experts worldwide. They also claim that there are definite differences between men and women who kill or harm their children. They say that women tend to be mentally ill, frequently suffering from post-partum depression. Men, on the other hand, feel rage, jealousy, hatred, and revenge when they kill their families.