In February 2020, Zhang Bo and his wife Chen Moumou divorced by agreement, agreeing that his daughter Zhang Moumou A would be raised by Chen Moumou, and his son Zhang Moumou B would be raised by Zhang Bo until he was 6 years old and then raised by Chen Moumou, and Zhang Bo would pay Chen Moumou 800,000 yuan in alimony in installments.
After Ye Chengchen learned about Zhang Bo's marriage and childbirth, he still continued to associate with Zhang Bo. Ye Chengchen believed that Zhang Bo's two children were an obstacle to his marriage to Zhang Bo and a burden to live together in the future, so the two of them killed Zhang Mou A and Zhang Mou B many times, and decided to commit the crime by causing an accidental high fall.
After that, Ye Chengchen urged Zhang Bo to commit the crime many times, and on the grounds that his family objected to the two living together because Zhang Bo had children, and would not meet and break up without solving the problem of the children, etc., he constantly urged and coerced Zhang Bo to kill people, and set a deadline for Zhang Bo. To facilitate the commission of the crime
Zhang Bo then tricked Chen Moumou into sending Zhang Moujia to his home. On the afternoon of November 2, 2020, Zhang Bo took advantage of his mother's outings to hold the legs of Zhang Moujia and Zhang Mouyi, who were playing on the bay window sill of the second bedroom on the 15th floor, and lifted them out of the window, causing Zhang Moujia to die of head injury, and Zhang Mouyi's brain and multiple organs in the thorax and abdominal cavity caused respiratory and circulatory failure and died after rescue efforts failed.
In December 2021, Zhang Bo and Ye Chengchen were sued by the court and sentenced to death. On January 19, 2022, both filed an appeal, and on May 11, 2022, they retracted their confessions in court, but the appeal was rejected and the original verdict was upheld. On January 31, 2024, in accordance with the execution order issued by the Supreme People's Court, the Chongqing Municipal No. 5 Intermediate People's Court executed Zhang Bo and Ye Chengchen.