On 18 February 2003, a mass killing occurred in Gaoheshanggou village, part of Yangjiao Township in Huludao's Lianshan district, Liaoning, China. Thirteen people across three households were killed in a combined stabbing and bludgeoning attack that lasted approximately one hour.
The perpetrator, 36-year-old Guo Zhongmin, had been involved in a zoning dispute with a neighbour, Zhang Baohua, over the construction of a vegetable greenhouse. Zhang sued Guo and won the case in court. Guo reportedly harbored a grudge afterward and came to believe that two other neighbours, Liu Changrui and Guo Zhongren, had supported Zhang during the legal proceedings.
On the day of the attack, Guo sent his wife and children away beforehand. In the afternoon, armed with a kitchen knife and a wooden stick, he entered the homes of his neighbours in succession. Eight people were killed at the residence of Liu Changrui, three at the residence of Guo Zhongren, and two at the residence of Zhang Baohua. Most victims showed signs of both bludgeoning and stabbing, with deaths attributed to head trauma or stab wounds to the head and torso. Guo sustained a cut to his left hand while fleeing the scene.
Huludao Municipal Public Security Bureau formed an investigative committee roughly 30 minutes after the crime was reported, and officers were dispatched to protect surviving relatives of the victims, including the family of Zhang Baohua. A Class A arrest warrant was issued, with Guo's photograph and description distributed for broadcast and publication, and security checks were established at transport hubs across Huludao's districts and counties. More than 1,000 officers of the Liaoning Provincial Public Security Bureau took part in the manhunt.
Over the following days, Guo travelled on foot through Lianshan district, receiving treatment for his hand at a clinic, begging for food, and, in one instance, threatening a household to obtain food, clothing, and money. He later stole pesticide and a bicycle from an acquaintance's store before fleeing the city, prompting police to alert public security bureaus in neighbouring Anshan and Jinzhou in anticipation that he would attempt to cross the provincial border into Hebei.
On 23 February 2003, Guo was located at a train station in Shahe Town, Suizhong County. As police moved to arrest him, he ingested pesticide he was carrying and died at the scene despite resuscitation attempts.