2023 New Taipei City junior high school stabbing

On December 25, 2023, during the noon lunch break at a junior high school in Tucheng District, New Taipei City, Taiwan, a dispute broke out after a female student surnamed Lin left a classroom belonging to a male student surnamed Yang, allegedly slamming the door. Yang reminded her to be careful with school property, which upset Lin. She returned to her own class and sought support from a male classmate surnamed Guo, whom she called her "sworn brother." Guo and several other students then confronted Yang, and the dispute escalated into a physical altercation. During the confrontation, Guo produced a concealed switchblade and stabbed Yang in the neck and chest, inflicting ten stab wounds and causing massive blood loss.

Yang lost consciousness and was found by paramedics without breathing or a pulse. He was taken to Far Eastern Memorial Hospital, where he was placed on ECMO and underwent emergency surgery. Although he briefly regained vital signs, he was pronounced dead on the evening of December 26, 2023. The New Taipei City Government's Education Department confirmed his death on the morning of December 27.

Police from the Tucheng Precinct took Guo and Lin, described as an alleged instigator, into custody on the night of the attack on suspicion of attempted murder; both were referred to the Juvenile Court of the New Taipei District Court. The court ordered Guo detained while releasing Lin into her guardian's custody. After Yang's death, prosecutors denied media reports that charges would be immediately upgraded. Investigators later suspected Lin of using a phone to collude with witnesses; two requests for a search warrant were denied before Lin voluntarily gave a statement on January 4, 2024, accompanied by counsel. On January 8, 2024, the Juvenile Court ordered her detained as well.

On March 21, 2024, the Juvenile Court transferred both Guo and Lin to prosecutors for further investigation. Prosecutors later obtained orders for detention incommunicado, citing risks of evidence destruction, collusion, or flight. On May 9, 2024, both were indicted on homicide charges, and the case proceeded under the confidentiality provisions of Taiwan's Juvenile Justice Act.

On September 30, 2024, the Taiwan New Taipei District Court issued a first-instance verdict, sentencing Guo to nine years' imprisonment and Lin to eight years'. Prosecutors called the sentences too lenient and appealed. On December 23, 2025, the Taiwan High Court issued a second-instance verdict, convicting both defendants of homicide and increasing the sentences to 12 years for Guo and 11 years for Lin; the ruling remained subject to further appeal. The victim's family criticized the sentences as too lenient and protested outside the court.

The case drew national attention, including comments from then-President Tsai Ing-wen and the three major candidates in the 2024 Taiwanese presidential election, as well as discussion of school security and juvenile justice policy by government ministries and civic organizations.