Looking through a family photo album with his mum, three-year-old Ashton Barrett points to one of the pictures: 'That's my mummy and daddy,' he said.

'My daddy is in heaven.'

• Two teenagers sentenced to 30 years for fatal knife attack on Connor Barrett, 20, at Hemsby party

• Connor Barrett killer on bail at the time of the murder

Ashton is a confident and chatty little boy, but he is growing up without his father.

Yesterday, his father's killers, Jesse Quaye, 18, and 15-year-old Ayomindy Bile, who can now be named after Judge Stephen Holt lifted reporting restrictions, were both sentenced to a minimum term of 15 years in custody after they were convicted of murder following a trial in November last year.

Mr Barrett, 20, of Abyssinia Close, Great Yarmouth, died as a result of a fatal stab wound following a 'joint attack' at a 21st birthday party on May 10, last year.

Sentencing Quaye and Bile at Norwich Crown Court, Judge Holt said: 'This is a deeply tragic case. There are no winners. A decent and loving young man has had his life taken, leaving his family and friends devastated and a young son's life decimated.

'The one message that must go out is young men who carry knives won't be able to pull them out and use them. If you use a knife and kill, you will spend a long time in prison - even if you are a boy.'

He described Mr Barrett as 'a thoroughly decent young man who had just taken on the responsibility of fatherhood' but added his words would be of 'little comfort' to Mr Barrett's family and friends who will 'have to live with the loss for the rest of their lives'.

He said Mr Barrett's son, Ashton, would have to 'grow up never knowing your father'.

At home with his mother, Kayleigh Simpson, in Yarmouth, Ashton is full of energy and eager to play. But Miss Simpson knows that what happened last summer will shape the person her son becomes.

Speaking ahead of yesterday's sentencing, his family said it was hard to put into words how much their lives had changed, but the 20-year-old would never be forgotten.

'It feels like the horrible part is finally over and we can start remembering Connor for who he was,' said his father, Lee Barrett.

'And having Ashton is like having a light in our lives.'

Mr Barrett, Miss Simpson and many of Connor's friends attended the sentencing yesterday. Miss Simpson missed only three days of the trial at Norwich Crown Court last year.

'Yeah, it was hard to hear, but I needed to,' she said.

'The first couple of days were the most difficult, seeing them in the dock, but after that, I guess I got tougher and I heard what happened over and over again.

'I never thought anything like this could happen to us, but it has and now I have to live with the fact that Ashton does not have a dad.

'He knows his daddy's not here any more. But I am going to have to tell him what happened when he's old enough to understand. I'll probably have to tell him again and again as he grows up, goes through school and other people ask where his dad is.'

Miss Simpson and Connor had known each other since childhood and were together for four years, separating just a few months before Connor was killed.

'We weren't together, but he was like a best friend,' she said.

'He was the most devoted dad. He would help out every day, anytime I asked. He loved him. Ashton is the last thing that's left of Connor.'

Connor's own father, Lee Barrett, moved from London to Norfolk in the 1980s. He said: 'We came from a bad part of the East End, there was violence, but we're talking about punch-ups, not knife crime.'

Before his son's violent death last May, Mr Barrett paid little attention to reports of youth gangs or youngsters carrying weapons.

With the court hearings over and the boys who killed Connor now behind bars, Mr Barrett said he can focus on moving forward.

'I will never, ever forget Connor,' he said. 'I don't want to. But now we can remember the happier times.'