Question: The criminal organization Kirksey Nix is reputedly the former leader of is based in what city?

Context articles: Vicente Castaño
Benjamín Arellano Félix
Francisco Rafael Arellano Félix
Kirksey Nix
Jesús Enrique Rejón Aguilar
Servando Gómez Martínez
Omar Treviño Morales
Samuel Flores Borrego
Dixie Mafia
Héctor Beltrán Leyva

José Vicente Castaño Gil aka El Profe (born July 2, 1957) is a Colombian paramilitary former leader of the United Self-Defense Forces of Colombia (AUC), a right-wing Colombian paramilitary organization.
 After demobilizing, he was accused of murdering his brother and former AUC leader Carlos Castaño and of narcotics trafficking by both the Colombian government and the government of the United States.
 In August 2004, the United States formally requested his extradition.
 Castaño remains, however, a fugitive and is the presumed chief of the criminal organization "Águilas Negras" made up of former AUC paramilitary members.
Benjamín Arellano Félix (born 12 March 1952) is a Mexican drug trafficker and former leader of the Mexican criminal organization known as the Tijuana Cartel or 'Arellano-Félix Organization'.
Francisco Rafael Arellano Félix (24 October 1949 – 18 October 2013) was a Mexican drug lord and former leader of the Tijuana Cartel, a drug trafficking organization.
 He was the oldest of seven brothers and headed the criminal organization early in the 1990s alongside them.
 Through his brother Benjamín, Francisco Rafael joined the Tijuana Cartel in 1989 following the arrest of Miguel Ángel Félix Gallardo, one of the most prominent drug czars in Mexico during the 1980s.
 When the Arellano Félix took control of the organization in the early 1990s, tensions with the rival Sinaloa Cartel prompted violent attacks and slayings from both fronts.
Kirksey McCord Nix Jr. (born 1943) is reputedly the former leader of the Dixie Mafia.
Jesús Enrique Rejón Aguilar (a.k.a. "Z-7", "El Mamito") is a former leader of the Mexican criminal organization known as Los Zetas.
 He was wanted by the governments of Mexico and USA until his capture on July 4, 2011 in Atizapán de Zaragoza, a Mexico City suburb.
Servando Gómez Martínez (born February 6, 1966), commonly referred to by his alias La Tuta (The Teacher) for once being a teacher, is a Mexican drug lord and former leader of the Knights Templar Cartel, a criminal organization based in the state of Michoacán.
 He is a former leader and founder member of La Familia Michoacana drug cartel, the split-off group of the Knights Templar.
 On February 27, 2015, he was arrested by Mexican security forces in Morelia, Michoacán.
Óscar Omar Treviño Morales (born January 26, 1974) is a convicted Mexican drug lord and former leader of Los Zetas, a criminal organization.
 He was one of Mexico's most-wanted drug lords.
 His brother is Miguel Treviño Morales, a former leader of the group.
 The authorities believe he was the successor of his brother, who was arrested on July 15, 2013.
Samuel Flores Borrego (a.k.a. Metro 3) (6 August 1972 – 2 September 2011) was a Mexican drug lord and high-ranking lieutenant of the Gulf Cartel.
 He was a former state judicial policeman who protected the ex-leader of the Gulf cartel, Osiel Cárdenas Guillén.
 Upon his arrest, Flores Borrego became the right-hand man of Jorge Eduardo Costilla Sánchez, the former leader of the criminal organization.
The Dixie Mafia is a criminal organization based in Biloxi, Mississippi that operates primarily in the Southern United States (hence the name "dixie").
 The group uses each member's talents in various crime categories to help move stolen merchandise, illegal alcohol, and illegal drugs.
 It is also known for violence.
Héctor Beltrán Leyva (born 15 February 1965) is a Mexican suspected drug lord and former leader of the Beltrán Leyva Cartel, a drug trafficking organization.
 He is the brother of Arturo Beltrán Leyva (deceased), former leader of the cartel.
 Héctor was the second-in-command and rose to the leadership of the criminal organization after his brother's death on 16 December 2009 during a confrontation with Mexican marines.