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).
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.
John Edward Walsh Jr. (born December 26, 1945) is an American television personality, criminal investigator, human rights, victim rights advocate, and the host/creator, of "America's Most Wanted".
 Walsh is known for his anti-crime activism, with which he became involved following the murder of his son, Adam, in 1981; in 2008, the late serial killer Ottis Toole was named as the killer of Walsh's son.
 Walsh was part owner of the now defunct Museum of Crime & Punishment in Washington, D.C.
 He also anchors an investigative documentary series, "The Hunt with John Walsh", which debuted on CNN in 2014.
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.
Patrick Wayne Kearney (born September 24, 1939) is an American serial killer who preyed on young men in California during the 1970s.
 He is sometimes referred to as "The Freeway Killer", a nickname he shares with two other – separate – serial killers, William Bonin and Randy Steven Kraft.
 Kearney may be among the most prolific serial killers in United States history, claiming possibly as many as 43 victims according to law enforcement.
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.
My Life Among the Serial Killers: Inside the Minds of the World's Most Notorious Murderers is a book written by Helen Morrison, M.D and Harold Goldberg.
 It presents the cases of ten serial killers, and touches on many more.
 Morrison spent hundreds of hours in face-to-face interviews, over many years, with several of the subjects.
 She uses the individual stories to explain and put forth her ideas on what makes a serial killer.
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.
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 Lee Lucas (August 23, 1936 – March 12, 2001) was an American serial killer who claimed to have killed over 3000 people; however, his confessions often contained inconsistencies or improbable logistics.
 Despite this, hundreds of cold cases were attributed to him and subsequently closed.

Question: Who wrote the film Henry: Portrait of a Serial Killer loosely based on real life serial killers Henry Lee Lucas and Ottis Toole?
Answer: John McNaughton