SHAH ALAM – The brutal killing of 16-year-old student Yap Shing Xuen at a school in Bandar Utama on Tuesday has left the nation reeling, not only from its violence but also from the haunting question of how a teenager could commit such an act.
Her mother, Wong Lee Ping, said her daughter was allegedly stabbed 200 times, suffering wounds to her neck, lungs and legs.
As investigations continue, an expert said the sheer number of stab wounds suggests a level of rage, compulsion or psychological detachment far beyond typical adolescent aggression.
Crime researcher R. Paneir Selvam said the excessive violence points to profound psychological turmoil, not a simple “crime of passion.”
“This attack appears less like a spontaneous ‘crime of passion’, which often involves strong personal emotions toward the victim and more like a manifestation of severe psychological disturbance,” he said.
Paneir noted that reports indicating the victim and the perpetrator had no prior interaction ruled out common motives such as romantic jealousy or personal conflict.
“The number of stab wounds suggests a level of rage, compulsion or psychological detachment beyond typical juvenile aggression,” he said.
He said that in criminology, such “overkill” behaviour is often linked to psychosis, obsessional thoughts or violent ideation and might occur in a dissociative state where the offender loses touch with reality.
Paneir pointed out that similar patterns could appear among youth with antisocial traits, fantasy-driven violence or escalating fixation behaviours, often left untreated.
“When a young adolescent commits such a premeditated act against a stranger, several contributing factors are often at play,” he said, adding that psychological instability, trauma and emotional detachment could have played a role.
He said the violence might have stemmed from deep-seated emotional pain, untreated mental health issues or detachment from reality, adding that some adolescents externalise distress through extreme aggression.
“Research shows some young offenders develop fantasies of control or violence. Without intervention, these fantasies can evolve into real actions,” he said.
Paneir added that social isolation and lack of empathy can cause adolescents to see others as objects, while impulse dysregulation, compounded by an undeveloped prefrontal cortex at age 14, might lead to catastrophic decisions.
“This incident isn’t simply an impulsive act. It points toward a profoundly disturbed psychological state, combined with environmental vulnerabilities, easy access to a weapon, exposure to violent influences and perhaps unnoticed warning signs,” he said.
Paneir said a 14-year-old capable of such cruelty is likely not “evil,” but rather a deeply troubled individual harbouring violent fantasies or severe psychological distress.
He urged authorities to strengthen early mental health interventions in schools, improve monitoring of youth exposure to harmful online content and tighten control over weapon access.
Paneir also highlighted findings from the United Kingdom’s College of Policing, which showed that exposure to violent imagery and extremist content online can desensitise young people to violence.
“Online spaces can reinforce violent ideologies, create belonging in harmful subcultures and normalise extreme acts,” he said, warning that access to “how-to” weapon guides further lowers the threshold for violence.
“Many youth offenders involved in knife crimes in the UK had previously searched online for weapon-related content or engaged with violent online subcultures before their crimes,” Paneir added.