Chen Jui-chin was born on July 25, 1949, in Chiayi County, Taiwan. He attended school and graduated from junior high school. After that, he studied in the horticulture department at National Chiayi University. Following his education, Chen volunteered to serve in the Air Force. He worked hard and achieved the rank of officer, eventually becoming a captain.

After his time in the military, Chen began working for CPC Corporation. However, he experienced job loss due to employee layoffs at the company. Rather than waiting for another position, he decided to leave and began searching for work as an oil allocation engineer. Unfortunately, he struggled to find a job in this field. Faced with the idea of retirement at a relatively young age, Chen applied for a new position at the Newport Township Office Finance Section.

In 1985, Chen Jui-chin killed his first wife, Tseng Pi-hsia. He claimed she died from a fall, but he had actually beaten her head against the ground. He collected $2.35 million NT from her life insurance. Just six months later, he married Wang Shu-ying, who had a son from a previous relationship that Chen adopted.

In 1988, in need of money, Chen pretended to discipline his adopted son and then caused his death by slapping him hard. He received $4.6 million NT in insurance money, again claiming it was an accident. In 1995, Chen targeted his biological son. He struck him with a heavy stone, causing fatal injuries, and claimed the boy had died in a car accident, profiting $4.72 million NT.

In 1996, Chen drove with Wang Shu-ying under the pretense of a trip. He then killed her with a wooden stick, disposing of her body to make it look like an accident. This time, he gained $11.37 million NT from her insurance policy.

After remarrying Yan Liqin in 1997, Chen's violent behavior continued. He caused the death of her 16-year-old son by giving him sleeping pills and then dropping him from the stairs. Yan suspected foul play, yet Chen tried to manipulate her understanding of the situation. During their divorce, he coerced her into paying him a breakup fee.

In 2003, Chen met Chen Yi-ling, an insurance saleswoman. After a brief relationship, he killed her in his jeep. He deceived her into taking sleeping pills, bound her, then assaulted and ultimately murdered her. Afterward, he stole her valuables and dumped her body off a cliff.

Chen was arrested on May 22, 2003, after he sought medical help for injuries. He confessed to the murders of Chen Yi-ling, his wives, and his children but later retracted his statements, claiming instead to know the whereabouts of some missing women.

In court, he was indicted for several crimes, including murder and rape. He received multiple death sentences and was ultimately executed on April 19, 2013, in Taichung Prison. After his execution, no one came to claim his body. It was eventually discarded by authorities, as even his ex-wife believed he should not be mourned.