Pedro Jacobo Contreras (born October 10, 1955) is a semi-retired Mexican "Luchador" or professional wrestler best known under the ring name Cachorro Mendoza.
 Cachorro Mendoza means "Cub Mendoza" in English and refers to the fact that he is the youngers of the Mendoza brothers Ringo, Indio and Freddy all of whom are "Luchadors".
 Over the years he's worked extensively for Empresa Mexicana de Lucha Libre (EMLL) and the Universal Wrestling Association (UWA), often teaming with his brothers, especially Ringo Mendoza.
 The Mendoza brothers have held the Mexican National Tag Team Championship on one occasion, and he has also held the Mexican National Middleweight Championship, the NWA World Middleweight Championship and the UWA World Middleweight Championship during his career.
 Cotreras briefly worked as Máscara Sagrada on the Mexican Independent circuit, using the outfit and name of the original Máscara Sagrada without permission.
 He retired from professional wrestling in the late 1990s but returned to the ring in 2009 to team with his brother Ringo Mendoza on a series of shows promoted by International Wrestling Revolution Group (IWRG).
Mike McNulty (1887 - 1965) was an old time, old style and old method boxing manager and trainer, who managed and trained several world champion boxers during the first half of the 20th century, including Mike O'Dowd, Johnny Ertel, Mike Gibbons and, also, trained Mike’s brother Tommy Gibbons, the Ring Boxing and International Boxing Hall of Fame.
 In 1965, Mike McNulty died at Studio City Convalescent Hospital in Studio City, California at the age of 78.
Frank Shamrock (born Frank Alisio Juarez, III; December 8, 1972) is an American former mixed martial artist.
 Shamrock was the first to hold the UFC Middleweight Championship (later renamed the UFC Light Heavyweight Championship) and retired as the four-time defending undefeated champion.
 Shamrock was the No. 1 ranked pound for pound UFC fighter in the world during his reign as the UFC Middleweight Champion.
 Shamrock has won numerous titles in other martial arts organizations, including the interim King of Pancrase title, the WEC Light Heavyweight Championship and the Strikeforce Middleweight Championship.
Michael Joseph O'Dowd (April 5, 1895 in St. Paul, Minnesota – July 28, 1957) was an American boxer who held the World Middleweight Championship from 1917 to 1920.
 He won the title on November 14, 1917 by knocking out Al McCoy in the sixth round after dropping him six times.
 O'Dowd was the only active boxing champion to fight at the front during World War I (1918, while serving in the U.S. Army).
 During his career he claimed victories over Hall of Famers Jack Britton, Mike Gibbons, Kid Lewis and Jeff Smith.
 On February 25, 1918, he held the legendary Harry Greb to a draw.
 O'Dowd was knocked out just once in his career, his last fight on March 16, 1923.
 He was inducted into the Minnesota Boxing Hall of Fame in 2011 and the International Boxing Hall of Fame in 2014.
Stanisław Kiecal (September 14, 1886 – October 15, 1910), better known in the boxing world as Stanley Ketchel, was a Polish American professional boxer who became one of the greatest World Middleweight Champions in history.
 He was nicknamed "The Michigan Assassin."
 He was murdered at a ranch in Conway, Missouri, at the age of 24.
Mike Gibbons (July 20, 1887 in St. Paul, Minnesota – August 31, 1956) was an American boxer from 1908 to 1922.
 The brother of heavyweight Tommy Gibbons, Mike claimed Middleweight Champion of the World status in 1909 following Stanley Ketchel's murder.
 Although he never won the title, Gibbons is regarded as one of the all-time best welter and middleweight boxers by historians.
 Statistical boxing website BoxRec lists Gibbons as the #18 ranked middleweight of all time, while "The Ring Magazine" founder Nat Fleischer placed him at #9.
 The International Boxing Research Organization rates Gibbons as the 17th best middleweight ever and boxing historian Bert Sugar placed him 92nd in his Top 100 Fighters catalogue.
 Gibbons retired due to deteriorating vision.
 Following his boxing career he entered business in his native St. Paul, and became a member of the Minnesota Athletic Commission.
 Gibbons was elected to the Ring Magazine Hall of Fame in 1958, the International Boxing Hall of Fame in 1992, the World Boxing Hall of Fame in 1997, and the Minnesota Boxing Hall of Fame in 2010.
Julio César Chávez Jr. vs. Sebastian Zbik was a Middleweight championship fight for the WBC Middleweight Championship.
 It has been the first time that the son of legendary boxing Champion Julio César Chávez, fought for a world title, Chávez went on to become the new WBC Middleweight Champion.
 The bout was on June 4th, 2011, at Staples Center, in Los Angeles, California and was broadcast on HBO.
Daniel Jeffery Henderson (born August 24, 1970) is an American former mixed martial artist and Olympic wrestler, who last competed as a middleweight in the Ultimate Fighting Championship.
 He was the last Strikeforce Light Heavyweight Champion and was the last Welterweight (80 kg ) and Middleweight (95 kg ) champion of Pride Fighting Championships.
 Additionally, Henderson was the Brazil Open '97 Tournament Champion, the UFC 17 Middleweight Tournament Champion, the Rings: King of Kings 1999 Tournament Champion and the Pride Weltwerweight Grand Prix Tournament Champion.
 During his career, Henderson also challenged for the UFC Middleweight Championship (2x), the UFC Light Heavyweight Championship and the Strikeforce Middleweight Championship.
 He was the first mixed martial artist to concurrently hold two titles in two different weight classes in a major MMA promotion.
 At the time of his retirement after UFC 204, he was the oldest fighter on the UFC roster.
 Known to be one of the greatest mixed martial artists of all time having defeated a total of seventeen MMA world champions across four major MMA promotions (UFC, PRIDE FC, Strikeforce, and RINGS).
Genaro Jacobo Contreras is a semi-retired Mexican professional wrestler, or "Luchador" in Spanish, and is a professional wrestling trainer for Consejo Mundial de Lucha Libre (CMLL).
 Contreras is best known under the ring name Ringo Mendoza, which he has used since his debut in 1968.
 Contreras has two brothers who were also professional wrestlers, Pedro Jacobo Contreras who worked as "Cachorro Mendoza" ("Cub Mendoza") and another brother who wrestled as "Indio Mendoza".
 Over the course of his career Ringo Mendoza held several Middleweight championships, including five NWA World Middleweight Championships, two Mexican National Middleweight Championships, one CMLL World Middleweight Championship and one Occidente Middleweight Championship.
 Mendoza wrestled his last match in 2011.
Jerome "Jeff Smith" Jefferds (April 23, 1891 – February 3, 1962) was an American professional boxer who held the Australian version of the World Middleweight Title during his career.
 Despite his relative anonymity, Smith faced off against some the best fighters of his era, including Harry Greb, Gene Tunney, Mike Gibbons, Georges Carpentier, Les Darcy and Tommy Loughran.
 Statistical boxing website BoxRec lists Smith as the 17th greatest middleweight ever, while Ring Magazine founder Nat Fleischer ranked Smith as the #10 Middleweight of all-time.
 He was inducted into the Ring Magazine Hall of Fame in 1969 and the International Boxing Hall of Fame in 2013.

Question: Mike Gibbons won the middleweight championship after the previous champion was found murdered where?
Answer: Missouri