Zhang Jun was born on August 5, 1966, in Hualin Village, Changde, Hunan, China. He was born into a poor family and was the youngest of seven children. His family's financial struggles affected his education. Due to these circumstances, Zhang dropped out of school during his first year of high school. After leaving school, he started participating in social activities, which was likely a way to find opportunities beyond his home. In 1989, Zhang faced legal trouble. He was arrested and sentenced to labor reform.

Zhang Jun began his crime spree in 1995. On December 22 of that year, he robbed the Chongqing Friendship store. During the robbery, he killed one person and stole gold jewelry worth 455,000 yuan.

The following year, on December 25, 1996, Zhang robbed Shanghai's first department store. He stole gold jewelry worth more than 630,000 yuan during that robbery.

On November 27, 1997, he targeted Changsha Friendship Mall. This time, he killed two people and stole gold jewelry worth 1.372 million yuan.

In December 1998, on the 20th, Zhang raided a public security checkpoint and a toll station in Hebei Province. He again killed two people during this attack.

The new year brought more crime. On January 4, 1999, Zhang robbed a gold jewelry cabinet in Wuhan Square, killing one person. He stole 30,000 yuan and 2.634 million in gold jewelry.

On August 15, 2000, Zhang robbed the president of the Agricultural Bank in Anxiang County. He killed two people and stole 16,000 yuan.

Just weeks later, on September 1, 2000, Zhang robbed a cash truck in Changde. This robbery resulted in the deaths of seven people, and he stole two small sub-machine guns and 20 bullets.

Zhang’s earlier crimes included several violent acts. In 1993, he was involved in an unsuccessful robbery with a friend named Liu Baogang. After injuring Liu, Zhang killed him with a hammer to avoid capture. He later killed a businessman from Hubei and two escorts to practice killing.

The police in Chongqing issued an arrest order for Zhang on September 19, 2000. They also arrested one of his mistresses, Quan Hongyan. When Zhang was caught, he had a military hand grenade with him.

Zhang Jun was tried in court. On April 14, 2001, he was sentenced to death for intentional homicide and robbery. He was executed by shooting on May 20, 2001.