Dr. Stanley Goldstein - Author and Psychologist

The Killer Across The Table, by John Douglas and Mark Olshaker describes the interviews of noted serial killers during which childhood and psychological similarities were found.
All had a troubled childhood, having experienced a far from "good-enough" parenting with much cruelty and/or sexual abuse and, often, a particularly damaging relatioinship with their mother. Which is not surprising since the mother-infant interaction is paramount when the basic ego capacities governing impulse control and thinking are formed.
These killers had a remarkable ability for psychological "splitting," separating and walling-off one aspect of their thinking and emotional life from another. Thus they could murder and bury a young child but later volunteer to join a search party while being concerned that their child get to school.
Rage and power were the domineering factors even in killings with a sexual element. The killer of a young girl from a neighboring home, who came to the killer's house to deliver Girl Scout cookies, knew from the moment he opened the door that he would kill her. This man, a high school teacher who lived with his mother, was told that she would refuse to see him and cut him from her will if he married. This caused him to break his engagement and added to his two types of rage. One that he could control, as when a driver cut him off. But the second he could not, as when the unlucky girl came to his house.
Another killer repeated his crime after being paroled following his rape and murder of a young woman. That these killers are not insane (which is a legal term) is evidenced by the care they took during the murders and in disposing of the bodies to avoid being caught.
This book evidences: the crucial need for more accurate assessment of those who are arrested; to consider even such unlikely suspects as family friends and loving relatives as the potential culprit; and to take reported suspicions seriously since many killing sprees would have been ended earlier had this been done, particularly those in hospitals by medical staff.
According to the authors: all serial killers have psychological conflicts between grandiosity and inadequacy; a sense of personal entitlement causing them to feel that they need not follow society's laws; and the ability to choose, making them deserving of capital punishment.