A teenager who brought a knife to Haute Vallée School in what a court heard was “revenge for a previous dispute” has pleaded guilty to six further offences.

The 15-year-old – who cannot be named due to his age – previously admitted two offences at the St Helier secondary school on Monday 10 February.

At the Magistrate’s Court today, he pleaded guilty to an attempt to commit robbery and possession of an offensive weapon in St Brelade on 7 February.

The teen also pleaded guilty to attempting to illegally enter La Haule Manor with intent to commit larceny, also on the 7 February.

Further offences admitted include a grave and criminal assault against a man on 6 February, and the theft of two pairs of sunglasses, a padel racquet and a bluetooth phone adapter from an unattended vehicle on the same day.

The youth also pleaded guilty to an assault committed in McDonald’s in September 2025.

Legal advisor Kerry Grieve, prosecuting, asked for the case to be transferred to the Royal Court for sentencing. 

She said: “There is little precedent I can point the panel to in terms of how the court has dealt with offences of this nature previously, for a youth of [the defendant]’s age and previous offending.

“However, the prosecution position is that the matter should be sent to the Royal Court, as a sentence in excess of 12 months is likely.”

The prosecutor told the court that the 15-year-old “admitted in interview that he brought a knife to Haute Vallée school to exact revenge for a previous dispute”.

“There are also messages that have been obtained from the defendant’s phone that support the robbery also being planned in order to try and get money to pay off the debt,” she added.

Advocate Adam Harrison, defending, suggested that the court give “anxious consideration” to whether the Royal Court would be “suitable” as a venue for sentencing – particularly given his age.

Magistrate Adam Clarke opted to send the case to the Royal Court.

“Some of the offences that you have pleaded guilty to are what’s called common law offences, which means potential sentence isn’t limited,” he explained to the teen.

He added that there was a “strong possibility” the teenager would receive a sentence in excess of 12 months, moving the case beyond the limits of the Magistrate’s Court.

While no bail application was advanced on his behalf, Ms Grieve submitted that the defendant should remain remanded in custody.

“The defendant presents a substantial risk of committing further offences, interfering with witnesses or the course of justice,” she said.

“Also, [we submit] that he should be remanded in custody for his own welfare.”

Her application was accepted and the 15-year-old was remanded in custody ahead of a sentencing hearing on the 21 April at the Royal Court.

A pre-sentence report was ordered with a potential additional psychological report to follow.

Mr Clarke told him: “A member of the probation service will be speaking to you on several occasions to understand your background and understand how we’ve got to where we’ve got to today.

“It is really important that you engage with that process.”

The States of Jersey Police said that officers “have worked tirelessly to bring this investigation to this point”.

Detective Inspector Christina Maclennan said: “We would like to sincerely thank the public and Liberty Bus for the vast amount of support, information, and vigilance that has shown over the past week.

“Your willingness to come forward and work with us has played a crucial role in allowing officers to act swiftly.”