1. H.H Holmes
Other known names: Herman webster Mudgett, Dr death, The torture doctor, the arch fiend 

2. Early Life
He was born to wealthy family and lived a privileged childhood
Showed unusual signs of intelligence at a young age. Still there were signs of a horrifying future ahead.
  His criminal life began with frauds and scams he did in college. 
He expressed an interest in medicine, which reportedly led him to practice surgery on animals.
As a medical student at the university of Michigan he stole corpses and used the bodies to make false insurance claims. 
Some accounts indicate that he may have been responsible for the death of a friend.

3. Additional background
The reason this guy is so infamous is that he created a hotel for his murder purposes they called it his murder castle.
H.H. Holmes moved to Chicago, Illinois. He found work as a pharmacist, using his now infamous alias, Dr. Henry H. Holmes. Eventually he took over the business and its original owner mysteriously disappeared.
The upper floors contained his living quarters and many small rooms where he tortured and killed his victims.
Some of these rooms had gas jets so that Holmes could asphyxiate his victims.

4. Continued  
During the 1893 Columbian Exposition, Holmes opened up his home as a hotel for visitors to the world's fair.
There were also trapdoors and chutes so that he could move the bodies down to the basement where he could burn his victims remains in a kiln 

5. Convicted crimes Crime Date Victims Punishment Insurance fraud
In July 1894
Life insurance companies
Jail time
Murder
November 17, 1894,
Benjamin Pitezel
Sentenced to death by hanging

6. Evidence of guilt
One of his partners Marion Hedgepeth sold him out for not getting her the money he promised her.
He killed Pitezel and then convinced Pitezel’s widow that her husband was still alive. 
Becoming concerned that the five Pitezel children might expose him, he went away with three of the children, eventually killing them.
He also confessed to killing 27 people but the range is believed to be in the hundreds. 
Holmes  killed Pitezel by knocking him unconscious with chloroform and setting his body on fire with the use of Benzene. In his confession, Holmes implied that Pitezel was still alive after he used the chloroform on him, prior to being set on fire.
May 7th, 1986 would be Holmes last day on earth as he was hung for murder

7. Sentencing and quotes
He was hung for the murder of Mr. Pietzel and many others soon to be found out about. 

8. Books, movies and TV shows
Books-The Devil in the White City: Murder, Magic, and Madness at the Fair That Changed AmericaThe Torture Doctor,The Shocking True Story of America's First Serial Killer ,The Monster of Sixty-Third Street American Gothic
Movies-documentary film on Holmes, H. H. Holmes: America's First Serial KillerDevil in the White City, an upcoming film 
American Horror Story: Hotel History Channel's Haunted HistoryIn episode 6 of the second season of Supernatural,

9. paragraph
I found I very hard to choose a theory but I decided to go with behavioral theory. I chose behavioral theory because Even though we don’t know what happened to make Mr. Holmes kill I believe it was something he went through as a young kid. He showed the first signs of a serial killer which happens to be the mutilation of animals which Holmes had experimented with as a young child. HH Holmes had a lot of aggression in him from what we don’t exactly know what its hard to believe that there wasn’t something that happened when he was younger. Also he lived a privileged childhood which means the he probably wasn’t picked on to often which means what ever the stressor was it was devastating to his mental state of mind. As he progressively got worse the older he got he started by killing animals then there was rumors he killed one of his friends as a child then when he went to college he stole dead bodies and then he also killed the first pharmacist he worked for and took over his business and then the murder castle to top it off. He also developed his own value system where he valued greed as the best possible attribute anyone could have. I believe him growing up in a wealthy family and not being punished to hard for his very bad actions lead to him believing that killing someone was not wrong. He committed some very violent crimes against humanity and he believed that the devil looked over him not god. With the crimes he committed the only theory based option we could pick is behavioral he was born a violent human and he used his violence in a very bad way. His day to day tendencies were violent when he was a child till the day he was captured just overall a sick human being who fueled his rage by killing innocent people. Finally I believe Herman Webster Mudgett (aka HH Holmes) began his killing rituals at very young age which changed his outlook on how to behave as a human and you put money with a sick twisted man scary things can happen and they did in this case.