It's been nearly a year since Xie Diao, a postgraduate student of the Chinese Academy of Sciences, was stabbed seven times to death by his high school classmate Zhou Kaixuan at a restaurant outside the school.

Xie Zhonghua, father of Xie Diao, has been immersed in grief in the past year: He often dreamed of his son, but then would suddenly awaken and start sobbing uncontrollably.

The case will finally be heard in Beijing First Intermediate People's Court on May 24. To get justice for his son, Xie Zhonghua took to the streets and publicized the case, gathering tens of thousands of signatures that he has submitted to the court. He hopes that, through his petition, the court would sentence Zhou to death.

According to the news portal Chinanews service, Xie Diao and Zhou Kaixuan had known each other for many years and shared the same dormitory when they were in high school in Chongqing. Both did well in their studies. After graduating from high school, Xie Diao went to Xidian University, while Zhou Kaixuan was also admitted to Sichuan University, but soon dropped out of school. Xi'an Jiaotong University later admitted Zhou in the second year. However, because of his addiction to games, he couldn't continue his studies. By that time, Xie had become a postgraduate in the Chinese Academy of Sciences.

After graduation, Zhou experienced frustration in finding a job and failed the civil service exam. According to the report quoting Xie Zhonghua, Xie Diao tried to comfort Zhou at a previous high school reunion, but they had a quarrel later during the role-playing game Werewolf.

Last year, a few days before the incident, Zhou sent a message to the students who attended the school reunion, saying, "Do you remember the gathering two years ago? I'll get even with him (Xie Diao)!"

Previous reports said Zhou confessed to police after the incident that what Xie had said in the gathering made him feel unpleasant in the past two years.

On Dec 12, 2018, Zhou went to Beijing for a trip. Two days later in the evening, Xie Diao met Zhou at a restaurant outside the school. He even took a photo for Zhou and sent it to their high school Wechat group.

The surveillance footage from the restaurant recorded everything that happened later. Before the meal was ready, Zhou suddenly took out a dagger and directly stabbed Xie's chest. While Xie covered his chest with both hands, standing up in panic, Zhou attacked him again, piercing Xie's neck several times. Xie then fell down to the ground but Zhou didn't stop. He rushed to Xie, pressed down on his body, and stabbed him again and again until Xie died. Zhou then rose, holding his arms and assuming a triumphant gesture.

Zhou was later arrested and confessed that he had bought the dagger online in advance.

Since losing their only child, Xie Zhonghua and his wife stopped going to work and have seen their health deteriorate. So far, they haven't received an apology from Zhou or his family.