[3] Duan was born on January 17, 1946,[4] in Qihe County, Shandong, and graduated from Xi'an Jiaotong University in August 1970.
He was later promoted to head of the provincial Intellectuals Works Office and deputy director of the Shandong Electronics Industry Bureau.
[2] From February 1994 to September 1995, he served as deputy party secretary of Liaocheng Prefecture, where he met his future mistress Liu Haiping (Chinese: 柳海平), who was 18 at the time and 30 years Duan's junior.
[1][2] At 5 pm on July 9, 2007, a powerful remote-controlled bomb exploded in a Honda sedan on Jianshe Road in central Jinan.
The explosion instantly killed the car's driver, Liu Haiping, whose upper torso landed more than 20 metres (66 ft) away.
[2][1] She had worked as a waitress in the cafeteria of the People's Congress, but was elevated to the position of a mid-level government official after she became Duan's mistress.
[1][7] To get rid of her, Duan asked policeman Chen Zhi (陈志), the husband of his niece, to create a "traffic accident".