A “psychopathic” schoolboy who stabbed a fellow pupil later admitted he had wanted to kill him, a court heard.

The 15-year-old who had nurtured a fantasy about “killing someone” plunged a pen knife into the boy’s shoulder in a school corridor

His victim was walking from a trumpet lesson when he was attacked. Although the pair were in the same year at Eirias High School in Colwyn Bay the boy told the court he had never spoken to his assailant.

As he entered his maths class he realised he was bleeding heavily from the wound which needed two stitches at hospital to close it up.

Mold Crown Court heard that when the boy’s attacker was arrested he revealed his obsession with killing and said he had been planning to stab his victim in the neck.

Prosecuting barrister Myles Wilson said: “He told police he’d stabbed a cow in the neck and killed a sheep. He said he chose his victim because he was the same age as him and the same size. He said he would not have taken much pride in killing a young child or someone who was elderly.

“He had been giving some thought to killing someone, this was not a spur of the moment decision.”

After his arrest the schoolboy was examined by a psychiatrist who could find no evidence he was suffering from a mental illness.

When a social worker asked the boy if his actions were “a cry for help” he replied “It wasn’t, I intended to do that”.

Mr Wilson said: “It was found he was a bright boy who had no remorse or empathy for what he had done. He said he had meant to kill his victim. The psychiatrist thought it ominous that his violent urges were not driven by anger and the evidence he had recently harmed animals was a sign of a psychopathic personality.”

The boy, now aged 16, has pleaded not guilty to attempted murder on February 11 this year, but he admitted an alternative charge of wounding with intent when it was put to him.

He is also charged with having a knife on school premises on February 8 and February 11 this year.

On the first occasion the boy showed the weapon, a folding pen knife with an 8cm blade, to a friend who filmed it on a mobile phone.

Three days later he was seen waving it around after he was asked to leave a class because he was disruptive.

When asked why he was outside by a fellow pupil he said the teacher was a “f…ing bitch” and he wanted to kill someone. He appeared to have been drinking and he was sent to see the deputy head who found a partly drunk bottle of whisky in his bag.

But he kept the knife in his pocket and absconded from a referral area he was told to stay in.

Spotting his victim he walked up behind him and shouted before stabbing him in the right shoulder.

The prosecutor added: “He (the defendant) later admitted to aiming for the boy’s neck. The boy felt pain but carried on walking into his classroom, while the defendant went back after him pointing the knife.

“He told police he wanted to stab him again but he was put off because he didn’t want to kill him in front of other pupils.”

The injured boy told the court via a video link: “I felt a thump on the back of my right shoulder. I felt there was liquid down my back and realised it was blood.”

His attacker was arrested in Rhyl later that evening telling passers-by he wanted to hand himself in for “attempted murder as he had stabbed someone in the neck”.

He told police that he didn’t need help and admitted if he was freed he would “just kill someone, successfully this time”.

Commenting on his predicament he said: “It’s a win, win situation, I get a roof over my head or I kill someone.”

The trial continues.