A high-profile case involving Zhang Koukou, who allegedly killed three men last year, was publicly heard at the Hanzhong Intermediate People's Court in Shaanxi province on Tuesday.

Zhang, a villager from Hanzhong, reportedly stabbed three neighbors with a knife on Feb 15, 2018, which was the New Year's Eve according to Chinese lunar calendar. The attack left two men dead on the spot while the third succumbed to injuries in hospital.

Local government said Zhang followed Wang Zhengjun and his elder brother on that day and on their way back home, Zhang allegedly used the knife to stab the two men several times. Then, the suspect came to the Wang's residence and reportedly killed the victims' father.

Zhang was detained on Feb 17 after he turned himself in to police.

The police said Zhang had a strong animus against the Wang family, because Zhang's mother died after Wang Zhengjun, the third son of the family, injured her head with a stick during a quarrel in August 1996.

The then 17-year-old Wang Zhengjun was sentenced to seven years in prison for causing intentional injury at the end of that year, and the family was ordered to pay more than 9,600 yuan ($1,510) in compensation.

Media reports said Zhang carried out the attack to take revenge for his mother.