The parents of a man killed in 2018 have spoken of their "hatred" for his murderer as they appealed for the public's help to solve the case.
Shane Fox, 26, was stabbed to death as he walked home in Wellingborough in Northamptonshire on 1 December 2018.
His parents Ian and Caroline Fox have made a fresh appeal for people to come forward with information as the charity Crimestoppers doubled its reward for the unsolved murder to £20,000.
Speaking to ITV News Anglia, the couple said that even nearly four years on, "every day is a nightmare".
"You wake up, partly you think it's not true - then you also think this person is roaming around living his life, when he's got no conscience," said Mrs Fox.
"He can't have [a conscience], knowing what he has done and still getting away with it."
Ian Fox said: "The feelings we have are obviously sadness, hatred to the person who has done it.
"What we have gone through, I wouldn't wish on my worst enemy," he said.
Mrs Fox said he hoped the increase in the reward money would "trigger someone to open up".
"I'm hoping it makes a difference, there is a chance that somebody could come forward and let some small bit of information out," Mr Fox added.
Shane Fox died from a knife wound to the chest while walking home to his flat in Nest Farm Crescent on the Hemmingwell Estate, at around 2am on 1 December 2018.
The suspect was described at the time as a black male in his 20s, wearing a dark-coloured puffa-style jacket with horizontal stitching.
Det Ch Insp Adam Pendlebury from Northamptonshire Police said: "We remain as determined as ever to find out who killed Shane and to get some much-needed answers for his family.
"I am also appealing for anyone who recognises the person in the CCTV image who was walking past The Well Café at 1.56am to get in touch with us as we believe they may have vital information in relation to this case."
Lydia Patsalides, of the charity Crimestoppers, said: "We hope that by appealing for anonymous information and doubling the reward, Shane's family and friends may finally have the answers and justice they deserve as their loved one has been cruelly taken away."
Ian Fox said the family had not lost hope.
"Hopefully now they've put the reward higher, it might make people stop and realise 'what can we do to help?'
"Whether it will or not, we'll just have to wait and see I'm afraid," he added.
"If it comes to the stage where they actually get somebody for it, at least we will know that person has been taken off the streets.
"It won't alter the fact that our son has gone but at least the person responsible has been brought to justice.
Mrs Fox said the family were constantly on edge, waiting for the phone call to say that Shane's killer had been caught.
Mr Fox added: "[As] each day, week, month goes by, we're still no nearer than we were four years ago and that is hard to swallow.
"It's just a total nightmare, it really is."
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