A report by Northern Ireland's Police Ombudsman into an IRA bomb that killed three people in Derry 25 years ago has said police had information of a booby trap bomb but did nothing to warn people.
The family of one of the victims said they have been the victims of lies and evasion by the police investigation into the atrocity.
Eugene Dalton, 54, died when the roof and three walls collapsed in a flat where he had gone to check on the whereabouts of a neighbour.
An inquiry by Ombudsman Dr Michael Maguire confirmed that RUC officers failed to alert people in the area about their fears of a bomb.
Mr Dalton and Sheila Lewis, 68, were killed at the scene while Gerard Curran, 57, died seven months after being pulled from rubble of the property in Derry's Creggan district in August 1988.
The Dalton family complained to the ombudsman's office 17 years after the deaths and today's report also revealed a flawed investigation by detectives involved in the hunt for the IRA killers.
Dr Maguire said responsibility for the deaths rested with the people who planted the bomb, but he also claimed that police failed to protect the victims and the subsequent criminal investigation was inadequate and incomplete.
He said he found no evidence to support a suggestion that police failed to do anything in order to protect an informer.
Some senior police officers refused to assist the ombudsman's review. It is also understood republicans in Derry failed to co-operate as well.
Sinn Féin said the party would not be making any comment until the report was made public.
Mr Dalton, a widower and father of six, Mrs Lewis, a widow, and Mr Curran went to the flat because they were concerned for their 32-year-old neighbour.
Mr Dalton climbed through a kitchen window, and was about to open the front door when the bomb went off. All three victims were Catholics.
The incident became known in Derry as the "Good Samaritan Bomb".
The ombudsman's investigation found the RUC inquiry was scaled down within a short period of time.
Detectives failed to finish comprehensive house-to-house inquiries, follow up on forensic work as well as preserve and manage investigation documentation.
There was also little or no communication with the families.
A number of suspects were arrested, but no-one has ever been charged with the murders.
The IRA later apologised, admitting they left a booby trap inside a wellington boot in the flat hallway in an attempt to kill members of an army search team.
In a statement, PSNI Deputy Chief Constable Judith Gillespie expressed sorrow for the loss of the three lives and said the police response would now be different.
She also said she was disappointed that a number of retired officers had declined to co-operate with the ombudsman's office.