Air cadet, 14, fatally stabbed in the neck by a former friend had been 'exploited' into dealing cannabis just two weeks earlier

An unarmed 14-year-old air cadet fatally stabbed in the neck by a former friend had been 'exploited' into dealing cannabis just two weeks earlier, police have revealed.

As Nathaniel Shani's killer – also 14 at the time – and a second teenager were given life sentences for his murder, detectives said his tragic death illustrated how easily children from loving, supportive families can be sucked into a deadly inner-city underworld.

Their stark warning over the latest victim of Britain's knife crime epidemic came as Nathaniel's devastated parents – who police say could not have known about his brief foray into a world of criminal gangs – movingly paid tribute to their 'courageous and charming' boy.

They called for a 'total ban of carrying knives in our streets' and urged schools to inform parents about concerns that their children were involved in crime so they could take 'responsibility' for keeping them out of trouble.

They also called for stiffer sentences for those convicted of offences involving knives.

The case comes after two 12-year-old boys last week became Britain's youngest murderers since James Bulger's killers after a being found guilty of stabbing Shawn Seesahai, 19, to death in a park in Wolverhampton.

A pupil at Manchester Communication Academy, Nathaniel took pride in his role as an air cadet, shining his shoes and ironing his shirt to make sure he looked the part.

A photograph released by his parents shows his delight at celebrating his 14th birthday with a card celebrating the 'amazing journey' through life that the family envisaged for him.

Instead, on September 15 last year the schoolboy – who was unarmed - was fatally stabbed in the neck during a petty dispute in a local shopping precinct in Harpurhey, north Manchester.

His devastated friends lied to police that it had been an argument about money, but detectives recovered Snapchat messages which revealed the true story.

One of his killers, Boy B, had taken a small amount of cannabis from another boy which had originally been provided to Nathaniel to sell in street deals.

Reacting angrily, in a bid to 'save face', a trial heard Nathaniel confronted Boy B, who was armed with a screwdriver, and Boy A – a 'good' friend of Nathaniel before they fell out - who had brought a knife.

The court heard Nathaniel had been 'goading' Boy A that he wouldn't use a knife before throwing a punch.

But gruesome CCTV footage showed how Nathaniel collapsed in the ensuing fight after being stabbed to the neck by Boy A.

After both were convicted of murder following a trial at Manchester Crown Court, the pair - neither of whom can be named due to their ages – were given life sentences on Wednesday.

Boy A, now 15, will serve a minimum term of 13 years in custody while Boy B, now 14, will have to serve a minimum of 10 years.

Paying tribute, his parents said: 'Nathaniel will be missed for many reasons, he was such a courageous young boy, charming with a great sense of humour, loving and caring who loved jokes and laughs, when he was inspired seeing Three Stooges' comedy team first time.

'Until his death, Nathaniel was never angry or mad at anyone.

'When he is bored, he will just crack a joke and every one would just burst into instant laughter whether it's at home or in school or playground.'

Describing the 'life-changing' impact of losing their son in such a traumatic way, they added: 'It's like a dream and that when we wake up, Nathaniel will be in his room sleeping.'

They are now calling for a meeting with Mayor of Greater Manchester Andy Burnham to discuss their demands for a tougher crackdown on knife crime.

Among their demands are a 'total ban of carrying knives in our streets', insisting parents 'take responsibility' for ensuring children don't carry knives, and requiring schools to disclose any concerns.

'More powers need to be given to police to pin down those carrying knives, prosecute and award longer sentences,' they added.

Afterwards the lead detective on the case, Det Chf Insp Gina Brennand, of Greater Manchester Police, revealed that the dealer who provided Nathaniel with the drugs has since been locked up for drugs offences.

She said investigators had established that Nathaniel had only been involved in drug dealing for about two weeks before he was murdered, with messages showing he had been told he could move onto selling cocaine if he did 'well' with cannabis.

'That street level exploitation, I would say, has led to Nathaniel's murder,' she said.

'Had the drugs not been stolen, the fight would never have taken place.

'That person has been the catalyst for Nathaniel's murder, and his parents would say that.'

DCI Brennand claimed Nathaniel and his friends were victims of 'child exploitation', saying 'they don't have the skills to know otherwise'.

'They might think it's cool, but they're not.

'They're just acting for someone else and being exploited. It happens every day, on streets of inner cities in the UK. And this is why children start to carry knives.

'It's awful, absolutely awful, it's devastating.

'These are vulnerable children who can't make decisions, who might want some money for a new pair of trainers, and so they start doing things because someone has approached them.'

She said Nathaniel's parents had responded by asking themselves 'What could we have done?' and 'What have we missed?'

'At least we could tell them that as far as we're aware, from Nathaniel's phone evidence, this is such a short period, just 14 days before he died that he started to get involved in dealing cannabis.

'They will always look at whether they could have done anything to prevent it, but they didn't know.

'It was such a short period of time, this is what makes it even more tragic.

'His own parents hadn't had the chance to become aware of what he was doing. They are mortified that they didn't know.

'What we've said to them as a team is that you'd have been lucky to know.'

At the pair's trial, Boy A unsuccessfully argued he had been acting in self-defence. The trial heard Boy B had 'encouraged' him to stab Nathaniel.

It was told that after falling out, Boy A and Nathaniel would meet up and engage in fights, but it was the cannabis theft by Boy B which lit the fuse for the confrontation which would end his life.

Following his death, the Greater Manchester wing of the Royal Air Force Cadets said it was 'extremely shocked and deeply saddened at the death of Nathaniel, who was a bright and popular young man'.

Asked what could be done to curb the scourge of knife crime, DCI Brennand said police could not tackle it alone.

'You need parents and families involved, you need council CCTV to be in the right place, you need security in the streets in the form of places where children can't hide, you need education at school,' she said.

'It seems to me that it doesn't matter how many children die from a knife wound from someone of a similar age, week in week out in the UK. That is not a preventative message to the children.

'I think the children might be the best people to ask how you stop it.

'I bet those who saw Nathaniel die won't carry a knife anymore.'