A simple silver butterfly is pinned above her heart on the vibrant purple sweater she wears in honour of the little boy she called ‘Mister D’. Her faced is etched with grief as she talks of her ‘special angel’ who will never get to unwrap the Christmas presents that sit under the family tree.

Yet, in her quiet agony, Nicole Hockley – mother of Dylan Hockley, the young British boy who died in America’s worst school massacre – is determined to focus on the positive.

‘Dylan brought untold fun and joy into our lives,’ she says with a smile. ‘Something good will come of this. His death will have meaning.’

As she sits beside her husband Ian, an IBM executive originally from Eastrea, Cambridgeshire, for this, their first interview since crazed gunman Adam Lanza went on a rampage which left 20 children and six teachers dead at Sandy Hook Elementary School, Nicole, 42, says she is speaking out to honour the memory of six-year-old Dylan, a blue-eyed imp who ‘captivated all with his smile’.

Dylan, who suffered from autism, died cradled in the arms of his devoted special needs teacher Anne Marie Murphy who was also killed. 

Ian, 42, moved his family from Eastleigh, Hampshire, to Newtown, Connecticut, two years ago in the belief that America would give his boys – Dylan and big brother Jake, eight – a better start in life.

He is sitting beside his wife to talk to me in a small room at Walnut Hill Community Church, shortly after delivering a passionate eulogy to his son to a packed congregation of almost 900 friends and family, including boys from Dylan’s Scout troop and classmates who escaped the rampage.

At the service, mourners were dressed in Dylan’s favourite purple as his beloved bedtime story Goodnight Moon was read. Hallelujah, a song from Shrek – which Dylan watched ‘endlessly’ – was sung by a family friend. A small urn containing Dylan’s remains sat at the front of the church, alongside a single purple balloon. He was cremated following a private funeral service on Wednesday.

On Friday, the family invited friends to what they dubbed a ‘celebration of life service’. As we talk, Ian smiles as his wife explains the significance of the butterflies they both wear. ‘When children are on the autism spectrum, some are rockers or they roll their heads. And some are flappers. Dylan was a flapper. Whenever he got excited or happy, no matter what he was doing, he would flap up and down, up and down and over and over. It was a sign of his joy.

‘I once asked him, “Why do you flap?” Because he had underdeveloped language skills, I was not expecting an answer but he replied, “Because I am a beautiful butterfly.” It meant a great deal to us because children with special needs are that much purer and more innocent and the idea of Dylan as a butterfly, now out of the cocoon of his body... it comforts me.’

The couple say they discussed the ‘butterfly effect’ in the dark hours after learning Dylan had perished when they returned to their £750,000 clapboard home in Sandy Hook which, by cruel irony, sits across the street from the one occupied by shooter Adam Lanza and his mother Nancy.

Lanza, who suffered from Asperger’s Syndrome, a form of autism, blasted his mother in the face before driving her black Honda Civic to the school where Nicole had just dropped off Dylan and Jake.

The ‘butterfly effect’ is a term used in chaos theory to explain how small changes in one area can  cause major changes in another, apparently unrelated, area. The term comes from the suggestion that the flapping of a butterfly’s wings in South America could cause a hurricane in Texas.

Nicole says: ‘We were talking about the idea of chaos theory. Dylan and all the other children and teachers who lost their lives are butterflies now. If one butterfly can cause a hurricane, then 26 butterflies can change the world.’

Ian explains that they believe the ‘hurricane’ will come in the form of tighter gun controls and in the introduction of laws to deter the mass slaughter of innocents which seems to occur with increasing frequency in America.

He says: ‘These deaths must not be in vain. Something must change, even though we don’t exactly know what form that change will take. Dylan is a beautiful butterfly who will change the world. His life must stand for something.’

A noticeboard in the church foyer contains snapshots of every stage of Dylan’s short life. In one he is a gurgling baby in his mother’s arms, in another, a little boy in a Superman shirt. Other shots show him wading in the ocean with his big brother and sitting astride a motorbike inside  a restaurant.

In every image he is beaming. Nicole says: ‘He was always smiling. He was a happy and free spirit, so pure and innocent. He was just pure joy. Dylan was a lovely, warm, little boy who loved cuddles.

‘He loved to be cuddled by us and also by his wonderful teacher. He died being cuddled in her arms. That brings us some comfort.’

For the memorial service, Dylan’s older brother Jake drew a ‘tree of life’ which was included in an eight-page order of service packed with more photographs. A clip of Dylan popping out of a jack-in-the-box was shown on an overhead projector as the organist played Somewhere Over The Rainbow.

Nicole told the congregation about her son’s ‘special bond’ with the teacher who died cuddling him: ‘Dylan looked at his class picture on our refrigerator every day and said: “That’s my class. There’s Mrs Murphy.” Last Friday, I was looking for Mrs Murphy because I knew no matter what, she would be with Dylan. When I was informed of his death, I dared to hope Mrs Murphy would still be alive but in my heart I knew she wouldn’t have left him.

‘She died trying to protect him and knowing that has eased our pain because Dylan was not alone.

‘We offer our heartfelt thanks to her for looking after our little boy. The sun will rise tomorrow – and tomorrow will be the start of a new period of healing, of peace and of positive change.’

Her husband fought back tears during the service as he raised his eyes towards heaven and said: ‘We’ll miss you Dylan. But we thank you for the happiness you brought us in so many ways. Thank you for filling our hearts and opening our eyes.

We thank you for being a wonderful son and an awesome little brother. We thank you and your friends for the legacy you leave behind. You are all in our hearts and minds forever. We love you so much Dylan.’

As he finished speaking, the congregation stood and applauded for two minutes.

Afterwards, outside the church, a sombre Jake released a bunch of 25 balloons – purple for the children, white for the adults. He then released a final single purple balloon for Dylan and waved it off.

Despite their own experiences with Dylan’s autism, Ian and Nicole say they have no idea what pushed Lanza to commit his heinous act.

Ian tells me: ‘I’m not qualified to talk about his [Lanza’s] autism.

‘All I can do it tell you who Dylan was and how he lived. That’s all that matters to us. That’s what we are working to honour.’

The family have set up a memorial fund in Dylan’s memory which will raise money for other children with autism and special needs.

Ian explains: ‘Children with special needs require additional support to help them realise their full potential and contribute positively to society. We hope to use any funds raised to support the development of children with special needs. What we saw happening with Dylan here at his school, where he had wonderful support and great teachers, we want to make that possible for other children in his memory.’

And Nicole adds: ‘So many people have reached out to us, wanting to do something. We know there is a lot of love from all over the world, especially Britain, and we want to turn that love into something positive. Instead of focusing on our family and our terrible loss, the best thing that could happen is for us to honour our beautiful angel, our very special little boy, through this fund.’

With that, tears fill her eyes again. She and Ian want to return to Jake, a boy desperately missing his younger brother.

The family plan to take a short break over Christmas, to escape the home that holds so many memories of their lost loved one. Dylan’s unopened presents will remain under the tree.

Their pastor Clive Calver, originally from London, is comforting the Hockleys with the story of another family, another community, which rebounded after a similar horror. Rev Calver says: ‘I’ve told Ian and Nicole the story of a little boy from another small town who cowered under a desk as a madman went on a gun rampage.

‘That little boy and that small town rose from the ashes and rebuilt themselves. That town was Dunblane and that boy was tennis player Andy Murray.

‘Out of Dunblane came much good. Laws were changed and lives were ultimately saved. I believe Sandy Hook and Dylan Hockley will leave the same legacy.

‘We will all be with this family forever, no matter where in the world we live.’

As they stand to leave, Ian and Nicole embrace. They will survive, they say. But they will never forget. ‘Dylan will always be in our hearts. Always,’ says Nicole. ‘He’s our special little angel.’

 VIDEO Heartbreaking moment Dylan's brother releases 25 balloons in his memory