The jury in the trial of a boy accused of murder has retired to consider its verdict.

The boy, now 16, is accused of murdering 14-year-old Christopher McBurnie, who was fatally stabbed in Ramsey on May 29 last year.

The defendant, who cannot be named for legal reasons, admits inflicting the fatal wound but claims he acted in self-defence. He denies murder.

After almost four weeks, all the evidence has been heard and the jury must now consider its verdict.

Jurors heard how Christopher and the defendant exchanged social media messages the previous day, during which insults and threats to kill were exchanged.

On May 29 last year, Christopher and another boy travelled from Castletown to Ramsey by bus. They were joined by others, with nine boys in the group by the time they reached the defendant’s home.

Once there, the defendant came outside and a fight between him and Christopher followed. Christopher suffered two stab wounds, a slash wound and a superficial defensive injury.

He died at the scene 40 minutes later despite desperate attempts to save him.

Deemster Graeme Cook gave further directions to the jury and summed up the evidence.

He explained that the prosecution argues the defendant is guilty of murder, rather than manslaughter, and had not acted in self-defence.

The prosecution says this was a prearranged fight and Christopher expected a fist fight. It argues that the defendant’s use of a knife was not reasonable.

However, the defence argues the defendant acted lawfully and regarded the messages, threats and insults as ‘all talk and bravado’. It says he acted tough online but never believed a fight would happen.

The defence argues his neurological conditions and cognitive impairment played a part. On the day, it says, he felt frightened and intimidated by the group outside.

Deemster Cook told jurors they must consider whether the defendant had goaded Christopher into coming to Ramsey or genuinely believed it was all talk.

The jury was told there were several questions to consider when reaching its verdict.

Jurors must decide whether the stabbing was deliberate or accidental. If accidental, the defendant should be found not guilty.

If deliberate, they must consider whether he acted in self-defence and whether he intended to kill or seriously harm Christopher.

If the jury finds he intended to kill or cause serious harm and was not acting in lawful self-defence, he would be guilty of murder.

If he acted in self-defence, jurors must consider whether the force used was reasonable. If it was, he should be acquitted. If it was unreasonable, and he understood his actions could cause some harm, even if not serious harm, he could be guilty of manslaughter.

Deemster Cook urged jurors to give the evidence ‘calm and careful consideration’, stressing that they were under no time pressure.

He said they should try to reach a unanimous verdict, although a majority decision could be considered later.