Question: Wyatt Earp was the brother of which US marshal of Tombstone?

full_context: Document 1: Hour of the Gun: Hour of the Gun is a 1967 Western film depicting Wyatt Earp and Doc Holliday during their 1881 battles against Ike Clanton and his brothers in the Gunfight at the O.K. Corral, and the gunfight's aftermath in and around Tombstone, Arizona, starring James Garner as Earp, Jason Robards as Holliday, and Robert Ryan as Clanton. The movie was directed by John Sturges.
Document 2: List of Old West gunfighters: This is a list of Old West gunfighters, referring to outlaws or lawmen, of the American frontier who gained fame or notoriety during the American Wild West or Old West. The term "gunslinger" is a modern, 20th-century invention, often used in cinema or other media to refer to men in the American Old West who had gained a reputation as being dangerous with a gun. A gunfighter may or may not be an outlaw or a lawman. An outlaw had usually been convicted of a crime, such as Black Bart, but may have only gained a reputation as operating outside the law, such as Ike Clanton. Some of those listed may have also served in law enforcement, like Marshal Burt Alvord who subsequently became an outlaw, and some outlaws like Johnny Ringo were deputized at one time or another. Some of the gunfighters listed included professional scouts, businessmen, and even doctors.
Document 3: Newton Earp: Newton Jasper Earp (October 7, 1837 – December 18, 1928) was the eldest child of Nicholas Porter Earp and Abigail Storm. He was the half-brother of Old West lawmen Wyatt, Virgil, and Morgan Earp.
Document 4: Gunfight at the O.K. Corral: The Gunfight at the O.K. Corral was a 30-second shootout between lawmen and members of a loosely organized group of outlaws called the Cowboys that took place at about 3:00 p.m. on Wednesday, October 26, 1881 in Tombstone, Arizona Territory. It is generally regarded as the most famous shootout in the history of the American Wild West. The gunfight was the result of a long-simmering feud, with Cowboys Billy Claiborne, Ike and Billy Clanton, and Tom and Frank McLaury on one side and town Marshal Virgil Earp, Special Policeman Morgan Earp, Special Policeman Wyatt Earp, and temporary policeman Doc Holliday on the other side. All three Earp brothers had been the target of repeated death threats made by the Cowboys, who objected to the Earps' interference in their illegal activities. Billy Clanton and both McLaury brothers were killed. Ike Clanton claimed that he was unarmed and ran from the fight, along with Billy Claiborne. Virgil, Morgan, and Doc Holliday were wounded, but Wyatt Earp was unharmed. The shootout has come to represent a period of the American Old West when the frontier was virtually an open range for outlaws, largely unopposed by law enforcement officers who were spread thin over vast territories.
Document 5: James Earp: James Cooksey Earp (June 28, 1841 – January 25, 1926) was a lesser known older brother of Old West lawman Virgil Earp and lawman/gambler Wyatt Earp. Unlike his brothers, he was a saloon-keeper and was not present at the Gunfight at the O.K. Corral on October 26, 1881.
Document 6: Wyatt Earp's Revenge: Wyatt Earp's Revenge is a 2012 American Western film about the legendary lawman Wyatt Earp. It is a fictionalized account of an actual Old West event, the slaying of beautiful singer Dora Hand in Dodge City, Kansas, when Earp was a deputy there. In one of its many instances of dramatic license, the movie depicts Hand as Earp's sweetheart. The film's framing device is a reporter's interview with an aging Earp, who reminisces about the tragedy. (Val Kilmer plays the older Earp, while Shawn Roberts plays the younger one.) The film was released on March 6, 2012, in the United States. The film was produced by Jeff Schenck and Barry Barnholtz and directed by Michael Feifer. The screenplay was written by Darren Benjamin Shepherd.
Document 7: Glenn Boyer: Glenn G. Boyer (January 5, 1924 - February 14, 2013) was a controversial author who published three books and a number of articles about Wyatt Earp and related figures in the American Old West. He was the first person to reveal the existence of Wyatt Earp's second wife, Mattie Blaylock. His publications were for many years regarded as the authoritative source on Wyatt Earp's life. However, when other experts began to seek evidence supporting Boyer's work, he would or could not prove the existence of documents that he said he owned and had cited as essential sources. In one case, an individual he cited as a key source was exposed as a complete fabrication. His reputation and the authenticity of his work was seriously damaged. Although he retained many supporters, his work became surrounded by controversy.
Document 8: Brooks–McFarland feud: The Brooks–McFarland feud was a family feud that took place between 1896 and 1902, in what is now the state of Oklahoma. It began after the death of Thomas Brooks on August 24, 1896. The Brooks family blamed the McFarlands and from there followed a series of confrontations that culminated in a historic shootout at Spokogee on September 22, 1902. During the shootout, Willis Brooks and two others were killed while a fourth man was seriously wounded. The feud ended about three weeks later, on October 10, 1902, when Jim McFarland was ambushed and killed near his home. According to the author Edward Herring: "The deaths of Willis Brooks and Jim McFarland signaled the end of an era when disputes were settled with gun smoke and hot lead. With them also died the old feud."
Document 9: Wyatt Earp: Wyatt Berry Stapp Earp (March 19, 1848 – January 13, 1929) was an American Old West gambler, a deputy sheriff in Pima County, and deputy town marshal in Tombstone, Arizona Territory, who took part in the Gunfight at the O.K. Corral, during which lawmen killed three outlaw cowboys. He is often mistakenly regarded as the central figure in the shootout in Tombstone, although his brother Virgil was Tombstone city marshal and deputy U.S. marshal that day, and had far more experience as a sheriff, constable, marshal, and soldier in combat.
Document 10: O.K. Corral hearing and aftermath: The O.K. Corral hearing and aftermath was the direct result of the 30-second Gunfight at the O.K. Corral in Tombstone, Arizona Territory on October 26, 1881. During that confrontation, Deputy U.S. Marshal and Tombstone Town Marshal Virgil Earp, Assistant Town Marshal Morgan Earp, and temporary deputy marshals Wyatt Earp and Doc Holliday shot and killed Billy Clanton, and Tom and Frank McLaury. Billy's brother Ike, who had repeatedly threatened to kill the Earps for some time, had been present at the gunfight but was unarmed and fled. He filed murder charges against the Earps and Doc Holliday on October 30.
Document 11: Virgil Earp: Virgil Walter Earp (July 18, 1843 – October 19, 1905) was both deputy U.S. marshal and Tombstone, Arizona City Marshal when he led his brothers Morgan and Wyatt and Doc Holliday in a confrontation with outlaw Cowboys at the Gunfight at the O.K. Corral on October 26, 1881. They killed brothers Tom and Frank McLaury and Billy Clanton. All three Earp brothers had been the target of repeated death threats made by the Cowboys who were upset by the Earps' interference in their illegal activities. All four lawmen were charged with murder by Ike Clanton, who had run from the gunfight. During a month-long preliminary hearing, Judge Wells Spicer exonerated the men, concluding they had been performing their duty.
Document 12: I Married Wyatt Earp: The 1976 book I Married Wyatt Earp was believed to be a memoir of his widow Josephine Earp, but was many years later described as a fraud, creative exercise, and a hoax. Originally published by the respected University of Arizona Press, it is the second best-selling book about western Deputy U.S. Marshal Wyatt Earp ever sold. It was regarded for many years as a factual account that shed considerable light on the life of Wyatt Earp and his brothers in Tombstone, Arizona Territory. It was cited in scholarly works, assigned as classroom work, and used as a source by filmmakers. Amateur Earp historian Glenn Boyer said that the retouched image on the cover of a scantily-clad woman was of Josephine in her 20s, and based on his statements, copies of the image were later sold at auction for up to $2,875.
Document 13: Warren Earp: Warren Baxter Earp (March 9, 1855 – July 6, 1900) was the youngest brother of Wyatt, Morgan, Virgil, James, and Newton Earp. Although he was not present during the Gunfight at the O.K. Corral, after Virgil was maimed in an ambush, Warren joined Wyatt and was in town when Morgan was assassinated. He also helped Wyatt in the hunt for the outlaws they believed responsible. Later in life, Warren developed a reputation as a bully and was killed in an argument in 1900.
Document 14: Wyatt Earp: Frontier Marshal: Wyatt Earp: Frontier Marshal (1931) was a best-selling but largely fictional biography of Wyatt Earp written by Stuart N. Lake and published by Houghton Mifflin Company. It was the first biography of Earp, supposedly written with his contributions. It established the Gunfight at the O.K. Corral in the public consciousness and conveyed a mythic story about Wyatt Earp as a fearless lawman in the American Old West. Earp and his wife Josephine Earp tried to control the account, threatening legal action to persuade Lake to exclude Earp's second wife from the book. When the book was published, neither woman was mentioned.
Document 15: Nicholas Porter Earp: Nicholas Porter Earp (September 6, 1813 – February 12, 1907) was the father of well-known Western lawmen Virgil, Wyatt, and Morgan, and their lesser-known brothers James and Warren Earp. He was a justice of the peace, a farmer, cooper, constable, bootlegger, wagon-master, and teacher.
ground_truth: Virgil Walter Earp