Where does this urge come from, and why is so powerful? If we all experienced this urge, would we be able to resist?

Is would it genetic, hormonal, biological, or cultural conditioning? Do serial killers have any control over their desires? We all experience rage and inappropriate sexual instincts, yet we have some sort of internal cage that keeps our inner monsters locked up. Call it morality or social programming, these internal blockades have long since been trampled down in the psychopathic killer. Not only have they let loose the monster within, they are virtual slaves to its beastly appetites. What sets them apart?

In a split second, she decided to fight. She had barely a chance against him, but she believed that if she didn't struggle while someone might still hear her, she'd die that day. Instinct told her that this man had murder on his mind.

Sharon kicked at him with her high-heeled shoes, screamed again and bit him hard. Yet he managed to slam her head on the concrete, dazing her. Fortunately another car came along, and her attacker ran off. She survived, but not long afterward another young woman did not.

Brudos is one of the most shocking serial killers ever and the subject of Ann Rule's book The Lust Killer. He abducted, tortured & mutilated young women in his garage, right under the noses of his wife and children. An analysis of the psychological factors that created this monster.

Serial killer Jerry Brudos, died March 28, 2006.

Eventually she was allowed to do household chores such as cooking, washing dishes, and cleaning up for the couple and their two children. Yet whenever Cameron yelled "Attention!" she was to strip off her clothes, stand on her tiptoes, and reach her hands to the top of the doorway between the living room and dining room.

Then one day the whole nightmare ended as quickly as it had begun.

A secret al-Qaeda cell in a wealthy neighborhood? Not quite.

Florida doctor and his wife make bombs on the weekend for fun, while building a huge arsenal of explosives, armor-piercing rockets, napalm and other unusual household chemicals. Together with their dentist friend, they planned to blow up a nearby Islamic center.

Mackay had a fascination with death. Apparently his father had regaled him with stories from the war about seeing his comrades shot down or blown up. Mackay himself spent a lot of time with the corpses of animals and birds. A neighbor saw him toss dead birds into the air and play with them. It's likely that he developed fantasies that involved the death process, which may have then become eroticized for him.

The British health system kept giving him a pass, permitting him to escalate his violence into repeated murders, including a priest who befriended him.

It stands to reason that violent imagery will affect certain people in a way that inspires them to act out. From the story that affects them, they acquire a frame and guidelines, and sometimes even interpret the film as a license to kill. Not everyone will be thus affected, but among those who are, it's safe to say there is such a thing as a "Copycat Effect" when the portrayal of violence grips a person so firmly that he or she decides follow the details of that specific template. Has the movie made him kill? No, but has it given him ideas and methods even victims? We can see that such things have occurred and are likely to continue to occur.

Steven's seven years of captivity are partially shared when a new boy is abducted and shares his fate as a sex slave to the aging pedophile.

Years later in 2002, Parnell was free and in his 70s, but Parnell's age and frailty did not prevent him from asking a caregiver to obtain a little African-American boy for him. Parnell offered the woman $500 for the service. At first, the woman doubted that the old man was serious, but when she became convinced that he was, she went to the authorities. A sting operation was arranged and Parnell was caught red handed in an attempt to perpetrate his twisted, criminal behavior on another child victim.

The sound of her flesh being slashed open. He's cutting her throat with the knife. Again and again and again.

It feels unreal as she watches droplets of her blood flung into the night. But it isn't. She feels no pain, but this is not a dream. This is happening. The man is slashing her throat.

The fear and the horror wrench through every nerve in her body. But she is completely aware.

The horrific injuries didnt stop with her throat being slashed. Yet, this attractive young woman who had been left for dead, survived. Her personal strength and a few miracles have given her life back.

On many occasions she chose to bypass the school bus altogether and instead hitchhiked to classes. Paula's boyfriend begged her not to hitchhike because of the inherent dangers, she ignored his pleas claiming that, "only nice people pick me up."

Michael Ross was later quoted saying to police during an interview "as soon as I saw her (Paula), she was dead." Paula was not Michael's first victim, nor would she be his last. In fact, before his capture he would claim responsibility for the murders of 8 young women.

While at school, Michael was socially active and joined several organizations. Moreover, he became involved in several relationships with some beautiful young co-eds, one to which he became engaged. However, the relationships always ended in failure and Michael's "dream of the perfect family began to be crowded by other fantasies disturbing, violent, sexual fantasies."

It didn't take long for his fantasies to spiral out of control.

However, there have been cases of men who have stopped themselves from killing again by going to the police to confess. Some actually express remorse, and might indicate that they'd been on drugs or were in some other state of diminished mental capacity during their crimes. They might also have come to the realization that, try as they might, they cannot stop themselves.

There are four basic victim types and sometimes their stories lead to the grave and sometimes to freedom. The slave masters are also very diverse psychologically in the way they practice this deadly game of dominance and submission.

And no one knew why.

The femme fatale was Nancy Spungen, very troubled young woman from a well-off Philadelphia family, who was determined to bed this young Sex Pistols celebrity, and bed him she did with a vengeance. Nobody could stand her as friends watched Sid become dominated by her. Ultimately he'd go cuckoo when he wasn't' with her.

Finally, their lives became classic co-dependencies: heroin and each other, until one morning she was found stabbed to death and he was charged with her murder.

Dr. Katherine Ramsland looks at the psychology of the various motives for which women kill: some for money, some for revenge, and most distressingly some to steal the growing child from their victim's womb.