Colleagues of a teacher who “snapped” and stabbed a school principal say they are still deeply shaken by the attack, as details of his severe mental health struggles have emerged in court.

Kim Ramchen, 37, has pleaded guilty to three charges, including intentionally causing injury, assault with a weapon, and unlawful assault, over the stabbing incident that took place in December.

The court heard that Ramchen took a 10-centimetre knife from the kitchen of Keysborough College and confronted principal Aaron Sykes after being informed that his teaching contract would not be renewed.

According to the prosecution, Ramchen entered the principal’s office in an aggressive state and targeted Sykes’ neck, leading to a violent struggle on the floor.

A teacher, Emma Pascoe, who was nearby, rushed to the scene after hearing screams and witnessed Ramchen standing over the principal with the knife. She later told the court she continues to suffer flashbacks and has turned to alcohol to cope with the trauma.

Another staff member, assistant principal Matthew Sloan, intervened and managed to pull Ramchen away, after which the school was placed into lockdown. However, Ramchen later returned armed with a larger kitchen knife and threatened the principal again before being restrained by staff.

School nurse Stacy Bender, who treated the injured principal, said the incident has deeply changed her perception of school safety, describing the environment as no longer feeling secure.

During police questioning, Ramchen admitted he “mentally snapped,” saying he intended only to incapacitate the principal and acted in a state of intense anger and emotional distress.

His defence argued that the incident was the result of a long-standing and complex mental health crisis, compounded by personal trauma, including a difficult childhood and ongoing family struggles.

The court was also told Ramchen has been diagnosed with autism, depressive disorders, and anxious distress, with experts linking his condition to the offending behaviour.

At the time of the incident, his marriage was reportedly breaking down, and he was struggling to understand the decision not to renew his contract.

His lawyer described the incident as arising from a “catastrophic mental health crisis.” Ramchen is due to be sentenced on Monday.