The murderer of a teenager who was buried in a makeshift grave is still at large while his friend was jailed over the killing, a court has heard.
Kieran Williams, 18, was stabbed more than 20 times and his body was dumped in a makeshift grave near the River Wear in Sunderland.
His friends Louis Hackett and Ben Cook were cleared of murder, but Hackett was convicted of manslaughter.
But the judge said the "real perpetrator or perpetrators" of the murder have not been caught, adding he was sure that neither Hackett or Cook had killed the boy or tried to set his body alight, reports Chronicle Live.
At Hackett's sentencing hearing at Newcastle Crown Court, Mr Justice Jay said: "This is the sort of case I will never forget as it's such an unusual case."
In an unexpected revelation, he added: "I don't believe either of these young men were the stabber, it was someone else."
The judge told Hackett: "You were not Kieran's murderer. It's difficult to be sure what happened that evening but certain hard facts are clear. Kieran was one of your best friends, he trusted you completely."
Kieran was found in a 0.75m hole around six weeks after going missing from home on April 18 last year, the day he was killed.
On May 31 last year the police discovered a grave that had been dug in a wooded area near a disused industrial estate by the Northern Spire bridge.
A pathologist found Kieran had suffered at least 20 stab wounds, including three to the front of his chest, two to his right torso, seven to his neck and a number of other wounds to his limbs.
One of the stab wounds had penetrated a membrane surrounding his heart, another penetrated his aorta and two entered his liver.
The court heard an attempt had been made to set Kieran on fire in the grave but the fire damage was limited to his clothes not his body.
Hackett persuaded Kieran to go out and meet him at the place where they would regularly meet to smoke cannabis. Mr Justice Jay said: "You knew something untoward was to happen to him, however you did not know he would suffer really serious harm, still less that he would be stabbed 23 times in a brutal attack.
"The jury clearly didn't think Ben Cook was the stabber either. I would endorse that conclusion.
"The better view is someone else is the stabber and he has still not been apprehended. I say that because my assessment of the evidence is neither of you was capable of an attack of this severity, particularly against a close friend.
"I also bear in mind the undetected print or prints and the neat way the grave was constructed then left after being filled in. Neither of you were capable of doing that.
"The unattributed prints remain a mystery. At least one other person left the grave in the tidy condition it was found."
The judge said both Hackett and Cook had told the jury a "complete pack of lies" but told Hackett: "You lied out of what I believe was a need to protect yourself and out of fear."
He added: "You were not aware a partly dug grave would be awaiting him. Had you been aware of the grave you would be guilty of murder."
Mr Justice Jay said Hackett had sought to blame Ben Cook for the stabbing after being confronted with the evidence of his fingerprint on and in the clay in the grave. He said: "You acted under the instruction of another or others in filling in the grave."
Sentencing the 20-year-old, of Fordenbridge Square, Sunderland, to five years in prison, the judge said: "The sentence I impose can't do justice to Kieran or his family. He was brutally murdered. So far the real perpetrator or perpetrators has got away with it. Justice has not been done but it won't be done by sentencing you for more than you are due."
The court heard Hackett has "quite severe learning disabilities". Toby Hedworth KC, defending, said: "The defendant had a role in securing the attendance of Kieran Williams at the place where the killing took place. Having got him there, he assisted in the back-filling of the grave.
"The offence was plainly planned by someone else and this defendant didn't realise any serious harm was intended to Kieran. He was substantially under the influence of another family."
Mr Hedworth said Hackett had been an "extremely close friend" of Kieran for many years and added: "He is genuinely sorry for what happened to Kieran. He spends most of his waking time thinking about what happened and believes this is going to live with him for the rest of his life.
"To say he regrets his actions is an understatement. While he knows it will not bring any comfort he wants to say to Kieran's mother how sorry he is for her loss and how he knows any words from him will never be enough.
"He promises to spend the rest of his life trying to make up for what's happened and wants to help others and help people in his situation make better choices."
Detective Chief Inspector Matt Steel, of Northumbria Police, said: “Our thoughts continue to be with Kieran’s family and loved ones following their loss.
"This is a truly tragic case in which a family have been left completely devastated and we will continue to support them wherever we can. We want to make it clear that violence of any kind is completely unacceptable – and is never the answer.
"When incidents do occur we are committed to doing all we can to bring those responsible to justice by putting them before the court. We can confirm this remains an open investigation and we are actively pursuing a number of lines of enquiry, and we will also continue to act on any new information which comes forward."
