The Court of Appeal has found that the sentence of a teenager who attempted to murder a woman he met on a dating app was too lenient.
The court said the element of planning and premeditation meant that, "even as attempted murders go", the offence had to be seen as being at the high end of the spectrum.
The DPP had argued that a review of the 11-year sentence imposed on the teenage boy after a five-year period was too early.
The now 17-year-old, who cannot be named because he is a minor, has been in custody since December 2017, when he lured Stephanie Ng to an isolated area at the seafront on Queen's Road, Dun Laoghaire.
After pleading guilty to attempted murder, he was sentenced to 11 years' detention in November 2019 with a review to begin on January 1, 2023.
The State appealed against the sentence on the grounds of "undue leniency".
The teenager met his 25-year-old victim on the Whisper social media app, where he had pretended to be 19.
The boy was just 15 when he tried to kill Ms Ng during their first face-to-face meeting, after suggesting they take a selfie by the water's edge.
There, he grabbed her from behind and choked her to unconsciousness before slashing her neck with a knife.
Gardai later found a book of drawings in his bedroom, containing a sketch of someone being cut up with a knife. The words 'serial killer' had been written on another page.
Ms Ng previously gave evidence of taking what she thought was her last breath, as the teenager tried to "choke the life" out of her before leaving her for dead.
She later felt that he was frustrated with himself for not having killed her.
Through tears, she told the Central Criminal Court that the boy had "destroyed" her life.
She attended a remote hearing of the Court of Appeal in May, where the DPP appealed against the leniency of the sentence imposed on her attacker.
The boy and his parents also attended remotely from the Oberstown Children Detention Campus.
Anne-Marie Lawlor SC told the court that the DPP wasn't taking issue with the sentence of 11 years, but said the review after five years did not reflect the gravity of the offence.
Patrick Gageby SC, for the teenager, argued that a very important part of the case was the possibility and probability of an emerging psychiatric illness or personality disorder in his client in the coming three or four years.
The president of the Court of Appeal, Justice George Birmingham, presiding with Justice McCarthy and Justice Isobel Kennedy, delivered judgment yesterday.
They concluded that the sentence was simply inadequate, and "while obviously the product of great care and attention, did not meet adequately the enormity of the offending behaviour".
The judges noted that the boy had requested a further sentence hearing if they found in favour of the DPP.
"A crime of attempted murder is, by definition, an offence of extreme seriousness," they said.
They noted that, for such a conviction, it had to be established that the offender acted with an intention to kill.
"In this case, the element of planning and premeditation means that even as attempted murders go, the offence has to be seen as being at the high end of the spectrum," the judges added.
They invited both parties to liaise with each other ahead of re-sentencing.