A laptop belonging to a teenager accused of murdering schoolboy Bailey Gwynne included a search for "how to get rid of someone annoying", a court heard.

Computer forensics expert Charles Bruce told the High Court in Aberdeen that the internet history also included a YouTube video entitled "14-year-old Bronx student stabs bully to death outside school" on October 4.

The evidence was heard on Thursday during the trial of a 16-year-old boy accused of murdering Bailey, also 16, at Cults Academy in Aberdeen.

Bailey died at Aberdeen Royal infirmary after suffering a stab wound to the heart during a fight with the accused on October 28 last year.

The laptop belonging to the accused, who cannot be named for legal reasons, included a search for "how to get rid of someone annoying" on October 7, three weeks before Bailey died.

Other search terms included "illegal knives UK", "Aberdeen stabbings per 1000", "difference between homicide and murder" and "knuckledusters UK", the court was told on Thursday.

The court heard analysts could not tell who had used the laptop, only the information viewed.

Ian Duguid, for the defence, suggested the searches had been taken out of context and selectively picked out by officers. He also quizzed Mr Bruce on what follow-up work was carried out.

The QC said: "Did you look up what was featured? Did anyone try to see what these links were?"

Mr Bruce said: "I was just requested to produce what I was asked to produce. I was under the impression that the inquiry team would be looking at these links."

The court was played a police interview with the accused recorded at the Kittybrewster custody centre the day after the stabbing.

The 16-year-old told police officers: "I had a knife because I've never fit in. I was trying to act tough and be cool."

When asked about owning knuckledusters, he said: "I had the [knuckleduster] to act cool as well."

The accused told officers he "bought the knife over the internet because they don't check if you're over 18".

He said he purchased the knife from Amazon for £10 and the knuckledusters elsewhere online for £40.

The teenager told police he "didn't have anything against" Bailey Gwynne but that he also had nothing in common with him.

'I did try to save him'

He told police he and Bailey had exchanged heated words after Bailey refused to give a biscuit to another boy and told the other boy that he "wouldn't want to get any fatter".

The accused said he then called Bailey’s mother "fat" and Bailey turned around to confront him.

The accused told officers he opened the knife and tried to "scare" Bailey with it.

"I didn't mean to but I stabbed him," he added.

Teacher Alasdair Smart then arrived and broke up the fight.

"At that point I noticed [Bailey] was bleeding. I noticed blood dripping from Bailey and he collapsed," the accused said.

The 16-year-old said he went to "try to stop the bleeding" but was told to "go stand around the corner" while others helped.

He said he was then taken to the office of deputy head David Strang, where he told the teacher he believed Bailey was “going to die” and that he was “going to prison”.

When the accused was told he was going to be charged with murder at the end of the police interview, he sobbed: "I did try to save him."

He added he did not believe Bailey had held him in a headlock, contrary to evidence given by witnesses earlier in the week.

Knife discovered in bin

Earlier, the court heard blood on a knife found in a bin at Cults Academy probably belonged to Bailey.

Forensic scientist Sarah Jones said there was a one-in-billion chance blood on the blade of the seven-inch folding knife did not belong to the 16-year-old.

DNA likely belonging to Bailey was also taken from the hand of the 16-year-old accused of his murder.

The court was told Ms Jones also examined clothing belonging to both boys and found a small hole in a blazer and shirt belonging to Bailey.

The murder charge against the 16-year-old claims he did "engage in fighting" with Bailey and struck him on the body with a knife.

In addition, the accused is also alleged to have had knives or "bladed instruments" as well as two knuckledusters "without reasonable excuse or lawful authority" on various occasions between August 1, 2013, and the day of the alleged murder.

The trial at the High Court in Aberdeen continues.