Question: Henry: Portrait of a Serial Killer is a 1986 American psychological horror crime film, the characters of Henry and Otis are loosely based on real life serial killers Henry Lee Lucas and which American drifter and serial killer who was convicted of six counts of murder?

Context articles: Ottis Toole
Cold North Killers: Canadian Serial Murder
American Gothic (novel)
Cold Fish
Futoshi Matsunaga
List of serial killers by number of victims
Confessions of a Serial Killer
Dennis Nilsen
Serial Killers Ink
Henry: Portrait of a Serial Killer

Ottis Elwood Toole (March 5, 1947 – September 15, 1996) was an American drifter and serial killer who was convicted of six counts of murder.
 Like his companion Henry Lee Lucas, Toole made confessions he later recanted, but which resulted in murder convictions.
 The discrediting of the case against Lucas for crimes in which Toole had offered corroborating statements created doubts as to whether either was a genuine serial killer or, as Hugh Aynesworth suggested, both were merely compliant interviewees whom police used to clear unsolved murders from the books.
 Toole received two death sentences, but on appeal they were commuted to life imprisonment.
 He died in his cell from cirrhosis, aged 49.
 Police attributed the murder of Adam Walsh to Toole on the basis of recanted statements.
 Lucas had backed Toole's confession to the Walsh murder, claiming he had been in possession of the victim's severed head.
Cold North Killers: Canadian Serial Murder is a 2012 Canadian non-fiction book written by Lee Mellor and published by Dundurn Press.
 It documents the lives of sixty Canadian serial killers, with the earliest being Edward H. Rulloff and the most recent being Russell Williams.
 The book uses Katherine Ramsland's interpretation of what constitutes a serial killer—someone who has killed at least two people on two separate occasions, and who attempted to or likely would have killed again—as outlined in her 2007 book "The Human Predator".
 "Cold North Killer's" own definition of what constitutes a Canadian serial killer includes both Canadians who committed murder abroad (such as Keith Hunter Jesperson and Gordon Stewart Northcott) and non-Canadians who committed murder in Canada (like William Dean Christenson and Earle Nelson).
American Gothic is a 1974 psychological horror novel by American writer Robert Bloch, a fictionalized portrayal of real life serial killer H. H. Holmes, who is renamed "G. Gordon Gregg" for the story.
Cold Fish (冷たい熱帯魚 , Tsumetai Nettaigyo ) is a 2010 Japanese horror-drama serial killer film directed by Sion Sono.
 The film is about a quiet and unambitious owner of a tropical fish shop whose life and family are taken over by a fellow fish entrepreneur who happens to be a serial killer.
 The film is loosely based on the exploits of two Tokyo serial killers, Sekine Gen and Hiroko Kazama, a husband and wife duo who owned a pet shop and murdered at least four people.
Futoshi Matsunaga (松永 太 , Matsunaga Futoshi , born April 28, 1961) is a Japanese serial killer who both defrauded and tortured his victims in what is publicly known as the Kitakyūshū Serial Murder Incident (北九州連続殺人事件 ).
 He was convicted of six counts of murder and one count of manslaughter between 1996 and 1998 and sentenced to die by hanging.
 He murdered his victims with an accomplice, Junko Ogata, who received a life sentence.
A serial killer is a person who murders three or more people, in two or more separate events over a period of time, for primarily psychological reasons.
 There are gaps of time between the killings, which may range from a few hours to many years.
 This list shows serial killers from the 20th century to present day by number of victims.
 In many cases, the exact number of victims assigned to a serial killer is not known, and even if that person is convicted of a few, there can be the possibility that he/she killed many more.
Confessions of a Serial Killer is a 1985 American horror film directed by Mark Blair.
 Preceding "" by one year, the film details a serial killer (based on Henry Lee Lucas) who, after being arrested, confesses to the murders of over 200 women.
Dennis Andrew Nilsen (born 23 November 1945) is a Scottish serial killer and necrophiliac, also known as the Muswell Hill Murderer and the Kindly Killer, who murdered at least 12 young men in a series of killings committed between 1978 and 1983 in London, England.
 Convicted of six counts of murder and two of attempted murder at the Old Bailey, Nilsen was sentenced to life imprisonment on 4 November 1983, with a recommendation that he serve a minimum of 25 years.
 He is currently incarcerated at HMP Full Sutton maximum security prison in Full Sutton in the East Riding of Yorkshire, England.
Serial Killers Ink is a website dedicated to selling "murderabilia" (collectibles related to murders, murderers or other violent crimes) and serial killer art, interviewing convicted serial killers and also serves as a meeting place for those interested or involved in the murderabilia industry.
Henry: Portrait of a Serial Killer is a 1986 American psychological horror crime film directed and co-written by John McNaughton about the random crime spree of a serial killer who seemingly operates with impunity.
 It stars Michael Rooker as the nomadic killer Henry, Tom Towles as Otis, a prison buddy with whom Henry is living, and Tracy Arnold as Becky, Otis's sister.
 The characters of Henry and Otis are loosely based on real life serial killers Henry Lee Lucas and Ottis Toole.