Planning - Research to develop character

Jeffrey Dahmer - American serial killer and sex offender. Dahmer murdered 17 men and boys – many of whom were of African or Asian descent – between 1978 and 1991, with the majority of the murders occurring between 1987 and 1991. His murders were particularly gruesome, involving rape, torture, dismemberment, necrophilia and cannibalism.
- Wikipedia.
He had a decent childhood. His father said as a young boy he was fascinated with the world around him and introduced Jeffrey to his collection of animal bones, which sparked Jeffrey's interest in animals. As he became more interested in animals he became curious to what they looked like inside. During the the stage of which when Jeffrey was going through puberty he began to collect roadkill and dissect the animals in the woods. His father believes this plays a big part it where Jeffrey's strange sexual desires. Jeffrey found it difficult to come to terms with his sexuality as he was homosexual.
He had a drinking problem through high school but was popular and known as the class clown. He later went onto joining the army but had to leave during his drink problem. He was living with his Grandmother when his consistent killings started (as he had killed a hitch hiker before).

Things I can take from this to help my own plot and story: unusual childhood, substance problems, could be popular and charismatic. Also from watching interviews he appears very calm and in control, very normal and generally a 'nice' guy. This should come into my consideration when choosing an actor for the character.

Ted Bundy - was an American serial killer active between 1974 and 1978. He escaped twice from county jails before his final apprehension in February 1978. Bundy was executed by electric chair for his last murder by the state of Florida in January 1989.
After more than a decade of vigorous denials, he eventually confessed to over 30 murders, although the actual total of victims remains unknown. Estimates range from 26 to over 100, the general estimate being 35. Typically, Bundy would bludgeon his victims, then strangle them to death. He also engaged in rape and necrophilia.
- Wikipedia

Ted did not have the best childhood due to his mother having him out of wedlock and having her parents (Ted's grandparents) acting and telling Ted that they were his actual parents, and also telling him that his mother was his sister. His Grandfather used to be particularly violent towards the women. One time when his mother was sleeping Ted took all the knives from out of the kitchen and placed them around her, pointing towards her.
Some people believe Ted's first kill was in his teens, a very young girl that he knew who went missing. Most people believe that his first kill came after he found out the truth about his family and also after he had broken up with his girlfriend. All of Ted's victims were attractive females with long brown hair, usually worn in a middling parting - they shared these physical features with Ted's ex-girlfriend.
Ted blamed his murderous acts on pornography. He was also a very charming man and surprisingly had a lot of female admirers.

Things I can take from this to help my own plot and story: He also was very charismatic and could easily charm and manipulate, when he was younger he was very socially awkward and could not understand relationships between people, family issues could have driven his first kill.