Mark Rowntree is a British spree killer who was committed to a mental hospital after he admitted killing four people at random in the town of Bingley, West Yorkshire, during late 1975 and early 1976.
 Due to the timing of his spree, some of his victims were erroneously assumed to have been killed by the yorkshire ripper, which distracted police enquiries at the time.
Badlands is a 1973 American crime film written and directed by Terrence Malick, starring Martin Sheen and Sissy Spacek, and featuring Warren Oates and Ramon Bieri.
 The story, though fictional, is loosely based on the real-life murder spree of Charles Starkweather and his girlfriend, Caril Ann Fugate, in 1958, though that basis was not acknowledged when the film was released.
Jeffrey James Weise (August 8, 1988 – March 21, 2005) was an American teenage mass murderer and spree killer, who was a student at Red Lake Senior High School in Red Lake, Minnesota, located on the reservation of the Ojibwe people.
 He murdered nine people in a shooting spree on March 21, 2005.
 He killed his grandfather and his grandfather's companion before going to the reservation high school, where he murdered seven more people and wounded five others.
 He committed suicide before being captured by police.
Michael Allen Silka (August 20, 1958 – May 19, 1984) was an American spree killer who is believed to have killed nine people in Alaska during May 1984, primarily in the small village of Manley Hot Springs.
 The spree culminated in a shootout with Alaska State Troopers in the Alaskan wilderness in which Silka was shot and killed.
 The motives for Silka's actions remain unclear.
Daniel Gonzalez (1980 – 9 August 2007), also known as the Freddy Krueger Killer and the Mummy's Boy Killer, was a spree killer who killed four people and injured two others during two days across London and Sussex in September 2004.
 His mother had previously written a letter to her MP criticising the fact that a serious incident had to occur before he could receive mental help.
 In her letter, she rhetorically asked "...does my son have to commit murder to get help?"
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Ronald Adrin Gray (born August 14, 1965) is an American spree killer whose convictions include four counts of murder, one count of attempted murder and eight counts of rape.
 His crimes were committed when he was in the United States Army, stationed at Fort Bragg, North Carolina.
 He was tried and convicted by military courts, and was sentenced to be put to death.
 His execution by lethal injection would be the first performed by the United States military since the execution of John A. Bennett for rape and attempted murder in 1961.
 On November 26, 2008, a federal judge issued a stay of execution stopping the planned December 10 execution.
 On January 26, 2012, the Army Court of Criminal Appeals denied relief in Gray's case.
 Gray's lawyers plan to appeal to the Court of Appeals for the Armed Forces.
Joseph "Josef" Schwab (1961 – June 1987) was a German tourist and spree killer who murdered five people in the Top End region of the Northern Territory and Western Australia in June 1987.
 Schwab was dubbed "The Kimberley Killer" by the Australian press after the region in which he committed the murders.
Leslie "Joe Goebbels" Irvin (April 2, 1924 – November 9, 1983) was an American serial killer whose killing spree in the early 1950s terrorized residents of southwestern Indiana and whose Supreme Court case set a precedent for ensuring a fair trial for defendants even in the wake of a great deal of pretrial publicity.
Red John is a fictional character and the primary antagonist of the CBS crime drama "The Mentalist" for the first five seasons and half of the sixth.
 As a serial killer, he is believed to have begun his killing spree in 1988, and has, with his operatives and acolytes, killed more than 70 people in California, Nevada, and Mexico, throughout his murder spree.
 Five years prior to the action of the first episode, he murdered the wife and the daughter of Patrick Jane (Simon Baker), making Jane his dedicated nemesis.
Charles Raymond "Charlie" Starkweather (November 24, 1938 – June 25, 1959) was an American teenaged spree killer who murdered eleven people in the states of Nebraska and Wyoming in a two-month murder spree between December 1957 and January 1958.
 All but one of Starkweather's victims were killed between January 21 and January 29, 1958, the date of his arrest.
 During the murders committed in 1958, Starkweather was accompanied by his 14-year-old girlfriend, Caril Ann Fugate.

Question: In what states were eleven people murdered by the American teenaged spree killer whose murder spree the film Badlands is based on?
Answer: Nebraska and Wyoming