Between 13 and 15 February 2004, four Yunnan University students were fatally bludgeoned in a dormitory residence in Kunming, Yunnan, China. The perpetrator, fellow student Ma Jiajue, was arrested in March 2004 after the murders were discovered. Ma was convicted of four counts of murder in April 2004 and executed in June of the same year.

In his confession, Ma claimed that several days before the murders, he, Shao Ruijie, and several other classmates had played a game of cards. Ma stated that Shao had accused him of cheating, calling him a "bad person" and remarking "No wonder Gong Bo didn't invite you to his birthday party". Ma considered Shao his best friend and immediately plotted his murder. Ma also decided to kill Gong Bo based on Shao's comment, as well as Tang Xueli, seeing the third roommate as a potential obstacle. Ma also said that the later victims had bullied him regarding his plans for the Chinese New Year holiday, as his work kept Ma from having much leisure.

In an episode of Behind the Headlines with Wen Tao , aired on the night of 1 October 2013, criminal psychologist Li Meijin said that Shao had revealed Ma's secret habit of soliciting sex workers and that this was the actual reason behind the murders.
(From Wiki)