Question: What terrorist group killed David Berger in Munich, West Germany during the 1972 Olympics?
Context: Knut Knudsen (born 12 October 1950) is a retired Norwegian road and track cyclist.  As an amateur he competed on track in the individual 4000 m pursuit at the 1968 and 1972 Olympics and 1973 World Champsionships, and won the event in 1972 and 1973.  At the 1972 Olympics he also placed fifth in the 100 km team time trial on the road.  He won the Norwegian National Road Race Championships in 1972 and 1973. The Munich massacre was an attack during the 1972 Summer Olympics in Munich, West Germany, at which eleven Israeli Olympic team members were taken hostage and eventually killed, along with a German police officer, by the Palestinian terrorist group Black September. Vera Nikolić (Serbian Cyrillic: Вера Николић; born 23 September 1948) is a Serbian coach and retired middle-distance runner who competed at the 1968 and 1972 Olympics.  She had her best achievements in the 800 m event, in which she won European titles in 1966 and 1971 and set a world record on 20 July 1968.  She came to the 1968 Olympics as a favorite, but due to the pressure of being the favorite she gave up her semifinal – after leading it for 300 m she suddenly stepped off the track, walked back to the start, sat down and took off her shoes.  She set her personal best in 800 m at the 1972 Olympics, but this was only enough for a fifth place. The FEAR militia (Forever Enduring, Always Ready) was an American terrorist group of between four and eleven individuals that the State of Georgia alleged in 2012 to have planned to destroy a dam and poison apple orchards in Washington State, set off explosives in Forsyth Park in Savannah, Georgia, and assassinate President Barack Obama.  Four of the individuals charged were soldiers stationed at Fort Stewart, Georgia.  The group killed two people in an attempt to prevent them from revealing their plans to the public. Vincent Paul Nihill (born 5 September 1939) is a retired British race walker.  He competed in the 50 km event at the 1964, 1968 and 1972 Olympics and won a silver medal in 1964.  In 1968 he suffered from the high altitude conditions of Mexico and collapsed at the 44th kilometre, which was his only defeat in 86 races between 1967 and 1970.  After that he focused on the 20 km distance, and won a European title in this event in 1969, followed by a bronze medal in 1971.  In July 1972 he set a world record in the 20 km, but finished only sixth at the 1972 Olympics.  He also competed in the 20 km walk in the 1976 Olympics, before retiring the following year. The 2012 Olympics one minute of silence campaign refers to an international campaign created to persuade the International Olympic Committee (IOC) to hold one minute of silence at the opening ceremony of the 2012 London Olympics to remember the Israeli athletes killed in the Munich massacre at the 1972 Olympics by the Palestinian terrorist organization Black September.  Support for the campaign came from a number of high-ranking officials and governments, including the United States Congress, U.S. President Barack Obama, U.S. Secretary of State Hillary Clinton, U.S. Republican Party presidential candidate Mitt Romney, the Italian Parliament, the Australian Parliament, the Canadian Parliament, the German Parliament, and German Foreign Minister Guido Westerwelle. The Olympia Schwimmhalle is an aquatics centre located in the Olympiapark in Munich, Germany.  It hosted the swimming, diving, water polo, and the swimming part of the modern pentathlon events at the 1972 Summer Olympics.  At the 1972 Olympics, the stadium had a 9000-seat capacity which was reduced to 1,500 soon after.  During the 1972 Olympics, the Olympic Records in all 29 Olympic swimming events were broken as well as the World Records in 20 events. Richard Joseph "Rick" Sanders (January 20, 1945 – October 18, 1972) was an American freestyle wrestler.  He won gold medals at the 1967 Pan American Games and 1969 World Championships, finishing second at the 1968 and 1972 Olympics and 1967 World Championships.  After the 1972 Olympics, while traveling to Greece, he was killed in a car accident in Skopje, Yugoslavia. The Erinnerungsort Olympia-Attentat is a memorial in the Munich Olympiapark for the victims of the Munich massacre during the 1972 Summer Olympics in Munich, West Germany, at which eleven Israeli Olympic team members were taken hostage and eventually killed, along with a German police officer, by the Palestinian terrorist group Black September. David Berger National Memorial honors the memory of David Mark Berger, a 28-year-old U.S.-born Israeli weightlifter who was one of 11 Israeli athletes killed by Palestinian terrorists in the Munich massacre at the 1972 Summer Olympics.  The memorial is dedicated to his memory and to the memory of the ten other athletes who were killed.
Answer: Black September