The family of the man brutally murdered by Paul Greatbanks two months after the PSNI failed to fully investigate an attack on another man want an explanation from the police.
Yesterday the Belfast Telegraph revealed four officers in Londonderry were disciplined after the Police Ombudsman "uncovered failures in the way the case had been progressed and supervised".
The investigation was sparked after Derry taxi driver John McLaughlin was left scarred for life when Greatbanks lifted a wooden bar stool and smashed it down on his head.
Despite reporting the attack the following day, and even telling the police that Greatbanks (below) lived right beside Strand Road police station, officers did not pursue the investigation until after Paddy Harkin was murdered.
It was then that Greatbanks walked into the police station dripping in blood and told police he had killed two men, believing that a second man he attacked, Paul Mythen, was also dead.
The murdered man's family now say they are owed an apology and an explanation and that the initial shock at hearing about the Ombudsman's findings has turned to anger.
John Harkin said that he and the rest of the family were left reeling by the news that has only added to the hellish nightmare they are already in.
"I was shocked to hear this and so was the rest of my family when I told them, but now we want answers," Mr Harkin said.
"We need to know why the attack on John McLaughlin was not taken seriously because we are convinced that if they had pushed ahead with that, Greatbanks probably would not have murdered our Paddy.
"The police owe us an apology and an explanation. If anyone else didn't bother doing their job they could get sacked, but this was a man's life that was lost and another man whose life has been ruined, and I think they should be in front of a judge."
Mr McLaughlin, along with Martina Anderson MEP, complained to the Police Ombudsman about the police's failure to fully investigate the attack on him.
The Sinn Fein politician added her voice to the call for the police to explain why they did not pursue the initial case.
"It is imperative that the police now give reassurances to the Harkin family that the discipline the four officers were given was appropriate," she said.
"If public confidence is to be restored the community must feel that if they take a complaint, especially a very serious complaint like the attack on John McLaughlin, to the police the police will fully investigate it.
"I know that John McLaughlin was left completely distraught when he discovered that Greatbanks went on to murder Paddy Harkin and he was racked with anguish that Paddy's death could have been prevented.
"The reality is that no one will ever know for sure and that is an awful way for the Harkin family to be left – wondering if their brother might have been alive today.
"The sad reality is that Greatbanks got the message that he could do something like that and not have to face the consequences."
The PSNI declined to make a comment until after Greatbanks is sentenced.