Adam Ellison's family said that his murderer is "living amongst us" in a plea for people to come forward with information about his killing.
The 29-year-old was stabbed to death during a night out in Prescot in the early hours of November 4, 2017. He was attacked by two men on a scrambler bike on Marktet Place and stabbed in the neck.
Adam was rushed to hospital, after being stabbed with the unknown weapon, but was pronounced dead shortly after 2am. In the years since his murder a number of arrests have been made but, to date, nobody has been charged.
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A BBC One documentary about his murder, titled 'True Crime: Our Adam', aired at 8.30pm on Monday (March 28). It followed Adam's family as they continue to raise awareness about his case and saw his sisters Joanne and Nicola revisit the spot where Adam was killed.
Following the broadcast of the show, a message was posted on the Facebook page ADAM - an official fundraising page run by his family and friends. The message was a plea for anyone with information about Adam's murder to come forward and a scathing message to those protecting his killer.
It said: “If you have any vital information however big or small it is, it could be the missing piece the police need to get Adam the justice he deserves and waited so long for. Knowing Adam I know he will be more worried about the pain this has and is causing to his family everyday - he was the kindest soul who always wanted to help and see people smile.
“People fear of speaking the truth which to some degree we understand, but this murderer has been living amongst us for over four years and could have been a mere few steps away from us. He is a threat to the public by being out in society, you are showing him loyalty by not coming forward with vital information, he has no loyalties to you and only wants to protect himself, you are feeding this killer’s ego by not coming forward for an innocent young man."
The message then continued: "Imagine yourself being on a night out and being murdered for no reason at all on your way home to your family but never making it home safe to see their faces again. "Please do the right thing… this waste of air who took Adam from us doesn’t deserve anymore time being free in society - you know who did this."
Before the documentary aired, Detective Chief Inspector Cath Cummings, who is the senior investigating officer on the case, said: "At the end of this year it will be five years since Adam’s death. I know that it has been five difficult years for his family and friends who have tried to come to terms with the sudden, unexpected and shocking loss of a loved one.
"Their agony has been compounded by the fact that, despite an ongoing investigation and a number of lines of enquiry being explored, his killer is still free to walk the streets. We regularly meet with Adam’s family and we are equally frustrated that this person is still at large and I know that the majority of law abiding people will be outraged that they are still free to go about their daily business.
"We know the answer lies in our communities but keeping quiet when you know something is misplaced loyalty that Adam’s killer does not deserve to have. I would appeal to anyone who has got the vital piece of information to search their consciences and come forward.
"If they don’t want to speak to the police then please speak anonymously to Crimestoppers and pass on what you know. Charging someone with Adam’s murder and seeing them go to prison does not bring Adam back but it will mean that this family, who have fought so hard for answers, will finally get the justice they deserve.
"I am sure anyone who has ever met Adam’s family, or who watches the programme this evening, won’t fail to be moved by what they have been through. Time is never a barrier to justice. Please come forward, tell us what you know and help us to help them."
Information can be supplied directly to the investigating team by going to www.mipp.police.uk and clicking on the Merseyside Police badge. Anyone with information which could assist the investigation can DM @MerPolCC or call 101. @CrimestoppersUK can also be contacted anonymously on 0800 555 111.
You can watch the documentary by clicking here.