This topic may go down like a lead balloon but anyway..
Serial killers are people who have murdered 3 or more people over 3 seperate occasions, murderers like Breivik are labled spree killers or mass murderers.
I think it is a really interesting subject, just trying to work out what is going through their heads to commit such crimes.
There seems to be 3 prevailant characterstics with serial killers.
1. Religion - Either very strong religious beliefs, god/the devil instructing them or just a plain old god complex.
2. Homosexuality - Normally struggling to come to terms with their sexual preference, feeling it is wrong and trying to make up for their 'immoral' behaviour. Other cases are an obsession to be as close to their sexual partner as possible.
3. Mother issues - Being unheathily close to their mothers, this isn't usually incest just needing over the top attention, their mother is their best friend etc.. Another mother issue is overly strict mothers which is often linked to religion.
Some examples of the above are;
Ed Gein (1,3)
Very, very strict mother who taught him the evils of woman and was deeply religious. Very close to his mother and loved her unconditionally.
When she passed away he was left to his own devices. His sexual frustration had built so much he became completely obsessed with the female body to excessive levels. He would study medical books of the female anatomy and when that was no longer enough he decided to dig up bodies to further his knowledge and carry out some of his sexual frustrations. When the grave yards were getting low on bodies he had to take things into his own hands and murder new women to inspect/abuse.
He also sidelined in costume and household design as he would create lamps from spines, light chains from lips, bras from breasts and knickers from...well you can guess. He would dance around his from lawn wearing his home made clothes. He was the inspiration to films such as Physcho, Silence of the Lambs and the Texas Chainsaw Massacre.
Rumoured to have murdered 3 people including his own brother. The death of his brother was initially put down to a tragic accident as he died in a forest fire long before Gein carried out his later acts but after they were uncovered it was believed he killed his brother to be closer to his mother.
Dennis Nilsen (2)
Homosexual who was desperate to find that partner who would never leave him, so he found a way to make sure they never did, murder them. In total 15 victims. On his arrest his victims were found all over his apartment and some in the drains as he attempted to flush their dismembered body parts down the toilet. His favourite method of murder was strangulation, often by a neck tie.
David Berkowitz 'Son of Sam' (1,3)
Adopted and told his mother had died whilst giving birth, this turned out to be a lie but he did not find out until after years of feeling immense guilt for causing the apparent death of his mother.
Originally Jewish but tried to adopt a few religions including Satanism which he eventually blamed for his killings even to go as far as to blame some of them on a cult and only taking direct responsibility for 3 of the 6 murders. Another reason he gave for the killings was he was instructed by his neighbour Sam who was the devil himself and David being driven mad by constantly barking dogs (owned by Sam)
Although his adopted parents loved him very much he struggled to feel any sense of belonging. He eventually tracked down his birth mother but was disappointed with what he had found as he had built her up to be something she could never live up to.
Often changing his story he eventually admitted he hated women and didn't want another child created in the manner he was and abandoned so he targetted couples making out in cars, often leaving the men unhamred.
When he was apprehended he couldn't stop himself laughing and smiling, an obvious desperation for attention was resolved as he became the most famous man in the world for those few moments.
The Zodiac Killer (1?)
Never caught, Arhtur Leigh Allen was suspected but died before being charged and no substantial evidence was ever found.
The Zodiac Killer was very intelligent and led the police along at will, often mocking their failure to catch him. The total number of his victims was unknown but there were 5 confirmed to be at the hands of this man(?). Zodiac often sent police complex codes that they would try to work out which contained clues to the crimes. The killer's targets were similar to Son of Sam, young couples in their cars making out. Without the killer ever being apprehended it's difficult to see what typical characteristics he displayed. He often talked of having complete power though which points to a god complex.
Jeffrey Dahmer (2)
Gay sexual deviant, necrophile and cannibal. A desperation to be as close to his partners as possible so he would go as far as boiling them and eating them. 17 victims in total, many found scattered around and even in pots and pans in his apartment. Used various methods for his murders including drugging, a power saw and injections of acid!
One of his victimes (a 14 year old boy) even managed to escape, he ran down the street naked and concerned neighbours called the police. When they arrived Dahmer managed to convince them the boy was his 19 year old lover, was drunk and they had an argument. Amazingly the police allowed Dahmer to take the victim back to his apartment despite much protest from the neighbours. The child was later murdered by Dahmer.