Wang Zhijian, born in 1966 in Tianjin, China, was a former port supervisor. He married and had a son, but the marriage ended in divorce in 2004. In 1996, Wang met Zhang Meng, a university graduate working at a shipping company, at a brokerage firm. They began a tumultuous relationship, complicated by Zhang's existing marriage. 

In 2008, Wang traveled to Singapore on a social visit pass to stay with Zhang, who was renting a flat in Yishun with her daughter, Feng Jianyu, and two tenants, Yang Jie and her daughter, Li Meilin. During his stay, Wang claimed he was subjected to humiliation and mistreatment by Zhang, including being confined to her bedroom and forced to use plastic bags for sanitation. He also alleged that he was made to eat leftovers and was prohibited from interacting with others in the flat.

On the night of September 18, 2008, after an argument with Zhang, Wang retrieved a serrated knife from the kitchen and stabbed her multiple times in her bedroom. Her daughter, Feng Jianyu, awakened by the commotion, entered the room and was also fatally stabbed. Wang then proceeded to the room of the tenants, Yang Jie and her daughter Li Meilin. He attacked Li, inflicting severe injuries. Yang attempted to escape by climbing out of the kitchen window but was allegedly slashed on the fingers by Wang, causing her to fall six stories to her death. Wang then returned to Li, who had hidden in the kitchen toilet, and continued his assault until he believed she was dead. 

After the attacks, Wang showered, changed clothes, and prepared to flee but was apprehended by police the following day. Wang was charged with three counts of murder and one count of attempted murder. During his trial, he claimed diminished responsibility due to an adjustment disorder. The High Court initially convicted him of one count of murder and two counts of culpable homicide not amounting to murder. However, upon appeal, the Court of Appeal overturned the lesser convictions, finding that Wang had the intent to kill all three victims. He was sentenced to death and executed by hanging on May 20, 2016.