Jeremy Bushell, 44, and Kate's mother Suzanne, 41, appealed for anyone shielding the killer to come forward and say where he was. "I would not want anyone else to suffer as we have suffered," said Mrs Bushell.
The grieving couple spoke for the first time since their 14-year-old daughter was murdered walking a neighbour's dog in Exeter, Devon.
Mr Bushell, a retired local government officer, found his daughter's body in the corner of the field a few hundred yards away from her home on 15 November. Her throat had been cut and today 120 police officers are still hunting her killer.
Mr and Mrs Bushell gave their first interview at their detached home in Burrator Drive, Exwick, Exeter, from where the murder scene can be seen from Kate's bedroom at the rear of the house. The distraught couple were surrounded by floral tributes and some of the 600 cards of condolence from all over the country as they spoke today.
Mr Bushell said: "If anybody knows the killer, or thinks they do, there is a very, very sick person there who is basically living in hell, and his private hell can only be relieved by coming forward."
Mrs Bushell said if someone was shielding the killer, it was in some ways human instinct to protect those you love.
But she asked them to say who it was adding: "I do think he needs help. I would not want anyone to suffer as we have suffered." Mrs Bushell felt Kate was "in the wrong place at the wrong time".
Kate was murdered as she walked a Jack Russell terrier named Gemma for neighbours who were away at the time.
"She went out as normal, we did not think anything of it, there was light," said Mrs Bushell adding that her daughter took out the dog to "help the neighbours".
Her husband added: "So many people walk dogs up and down that lane. We all thought it was a safe place and a safe lane. It could have been anyone. I do not think Kate was specifically targeted."
Asked whether he had heard any rumours that the lane was unsafe Mr Bushell said: "We were not aware of it. There was always that sort of fear in any community something could be unsafe. We have not heard anything specific.
"You cannot live your life in a cocoon. You have got to live it in the world where you are." Asked how they would come to terms with the loss of their daughter, Mrs Bushell said: "We will never forget Kate. She's always going to be with us, we had 14 lovely years with her."
And her husband added: "Everything you had hoped for for Kate is not there. It takes time to come to terms with that. I do not know how we are going to cope. Life has to go on. You cannot live in the past.
"We had such a fabulous 14 years which have always been a treasure to us.
"It would have been lovely if it had been a full life span."
Speaking of the hundreds of cards and letters they had received, Mr Bushell said: "It has been so much appreciated. The whole of the country has been carrying us, these expressions of love and the way people have reached out.
"Without that I do not know how we would have survived."
The couple said they were setting up a memorial fund for Kate following questions from a number of people who wanted to make donations.Reuse content