A coroner has found neither direct nor indirect evidence of collision between security forces and loyalists in the 1994 murder of pensioner Roseann Mallon in Co Tyrone.
The 76-year-old was sitting in her sister-in-law's house on the night of May 8 when she was shot dead by the UVF.
The spinster, who suffered with arthritis, was hit multiple times when gunmen indiscriminately opened fire on the bungalow at Cullenrammer Road on the edge of Dungannon.
The UVF said its notorious mid Ulster brigade was responsible and was targeting two of Ms Mallon's nephews - Christopher Mallon, who was not home at the time, and Martin Mallon, who lived half-a-mile away.
Both were involved with the republican movement.
An inquest into Ms Mallon's death heard that security forces had installed two cameras in the area to monitor the two men.
It heard evidence that the cameras were monitored by a soldier to establish daytime patterns, but were turned off at night to preserve battery life - and only showed the front of the house.
However, presiding coroner Lord Justice Weir questioned why RUC Special Branch had not handed over footage from the camera to the police investigating team led by Detective Chief Inspector Kenneth McFarland.
"This was, to say the least, deeply unsatisfactory," he said.
"Clearly a decision was taken at a senior level in SB not to share the video material or its existence with Mr McFarland who was a policeman of senior rank charged with the investigation of the most serious crime of murder."
In his findings, Lord Justice Weir mentioned evidence given by Mr McFarland to in which the retired officer described Special Branch as "a force within a force", and added: "If SB thought you didn't need to know you didn't know".
Five months after the murder of Ms Mallon, Special Branch handed over a list of car registrations that had been observed on the road that day, but there was a "discrepancy" between that list and those cars on the video footage, the inquest heard.
Lord Justice Weir said of the decision not to hand the tape to the murder investigation: "It is difficult to understand and has not been explained."
No-one has ever been convicted over Ms Mallon's death, although high-profile killer Billy Wright - who was murdered in the Maze prison in 1997 - and two other loyalists were arrested and questioned.
The interview notes had been held at Gough Barracks in Co Armagh and the inquest surmised that they had been destroyed. Police officers' journals were also not available.
Lord Justice Weir said of that: "I simply do not know what the practical effect of all or any of these matters may have been.
"Certainly, taken cumulatively, they do not inspire any feeling of confidence in the way in which the police investigation was conducted or the materials gathered in the course of it preserved so as to be available to the inquest or, perhaps, to some further investigative or prosecutorial endeavour in the future."
Concluding his findings, he told the inquest that he does "not find direct or indirect evidence of collusion or anything from which I could infer collusion from the evidence which has been brought before me".
Lord Justice Weir described Ms Mallon as "entirely innocent victim", "a defenceless lady of mature years and blameless character" killed in a "planned, unprovoked sectarian attack".
"The deceased was shot for no reason other than she happened to be a person present in a Catholic home."
None of the Mallon family were in court in Belfast to hear the findings.
Mark Thompson of Relatives for Justice, who has worked closely with the Mallon family, said last night: “Obviously Justice Weir couldn’t find evidence of collusion as it has all been destroyed, and so logically it is therefore self evident, and collusion could and should have been inferred."
He said the Mallon family will now study the findings and seek legal advice.
