Omar Moumeche was 16 when he attacked Dennis Clarke at Derby bus station in May 2021.

Now 18, he was sentenced on Friday after being found guilty of manslaughter in July.

Sky News looks at the laws on youth sentencing and what factors could have influenced the sentence in this case.

What was the crime?

Moumeche punched Mr Clarke once. The 82-year-old hit his head on the floor, fracturing his skull, and died of his injuries nine days later.

Moumeche had followed Mr Clarke to the bus station from a nearby shopping centre after Mr Clarke had told him and his two friends to stop messing around on the escalator.

No further action is being taken against two other teenage boys who were arrested in connection with the attack, according to Derbyshire Constabulary.

What happened next?

Moumeche was found guilty of manslaughter in July after the jury at a trial in the summer of 2022 were unable to reach a verdict.

He was sentenced to two years in youth detention on Friday.

What factors were at play in sentencing?

While Moumeche is 18 now, he was 16 at the time of the crime - so this is the age that is taken into account in his sentencing.

Judges sentencing children and young people are bound by guidelines and specific principles, Lynda Gibbs KC, dean of The Inns of Court College of Advocacy, tells Sky News.

"The reason why there's a different approach taken to sentencing children is because they are much more likely to be able to change their offending behaviour if they get positive support in detention, much more so than adults."

Rehabilitation and reintegration back into society are the guiding approaches, she says, "and those two things are much more important than the punishment".

"The principal aim of the youth justice system is to prevent reoffending," she says.

"The court has to have a deliberate aim not to criminalise children unnecessarily."

The risks of custody have to be taken into account, including how mingling with other young offenders could influence a child, Ms Gibbs says.

"A custodial sentence should always be a measure of last resort and only imposed if the offence is so serious that nothing else will do - and it clearly was the case here."

There are different custodial sentences that can be handed out to minors: detention and training orders (DTO) for a maximum of two years, longer custodial sentences for serious crimes and life sentences in the case of murder.

It would have been possible for the judge to impose a longer sentence "if the facts had been different", Ms Gibbs says.

Youth sentencing is focused on the individual, rather than just what they did. In this case, two years in youth detention was considered appropriate by Judge Shaun Smith.

At the sentencing, he acknowledged that "this is a case of such sentencing difficulty that I foresee nobody will be satisfied with what I do", the BBC reported.

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Mitigating circumstances

The court has to consider any mental health issues or learning difficulties the defendent has, Ms Gibbs says.

The young person's brain development will also be taken into account, she adds, bearing in mind that until the age of 25 the brain is not fully developed.

The judge said he accepted psychological reports, which said Moumeche had an emotional age of about 13 at the time of the incident.

Moumeche's lawyer, James Horne, told the court a doctor said "he would be overwhelmed in a secure setting and presents an increased risk of self-harm and he would need therapeutic support", DerbyshireLive reported.

"Through his teenage years, he experienced a number of social, familial and cultural issues which have had an effect on his upbringing."

He also said his client had no previous convictions.

The court will have taken into account Moumeche's "culpability in that offence, the extent to which it was planned, what his role was, whether he was aware or understood the consequences of what he did" in deciding the sentence, Ms Gibbs says.

The judge said while Moumeche was a "young man prone to outbursts of anger", he did not present a risk to the public, the BBC reported.