The PSNI Chief Constable is set to go to the Supreme Court to challenge rulings over the independence of investigations into Troubles killings.
Senior judges granted leave to appeal a decision that the force has not shown the practical impartiality for a new probe into the suspected military shooting of a woman in west Belfast 47 years ago.
Justices in London may also be asked to examine verdicts in the cases of the so-called Hooded Men and the loyalist Glenanne Gang series of murders.
Lord Chief Justice Sir Declan Mogan said: "This is really designed to ensure the law in relation to the independence of the police is clarified."
Police sought permission to mount challenges to the UK's highest court following decisions reached in three high-profile legacy-related proceedings.
In March the Court of Appeal held the PSNI's Legacy Investigation Branch (LIB) lacked the required independence to carry out further investigations into the death of Jean Smyth.
The 24-year-old mother of one was killed by a single shot to the head as she sat in a car on the Glen Road in June 1972.
At the time the Royal Ulster Constabulary informed her family that it was probably an IRA gunman who opened fire.
But records uncovered at the National Archives in Kew, London in 2014 suggest the British army's Military Reaction Force (MRF) fired shots in the area and were allegedly involved in her killing.
It was stressed during court hearings that Mrs Smyth was a wholly innocent person in the wrong place at the wrong time.
Counsel for the family had argued that fresh evidence links the British state's own agents to the killing of one of its citizens.
Leave to appeal the judgment was granted due to the establishment of a point of law of general public importance.
"The most pressing point is the independence point, because it cuts across a number of these cases," Sir Declan said.
Similar applications were brought in two other cases involving a series of loyalist murders and alleged torture at the hands of British security forces.
In July the Court of Appeal ruled that bereaved relatives are being denied their legitimate expectation that an independent police team will oversee a probe into the activities of the so-called Glenanne Gang, a terror unit linked to more than 100 murders during the 1970s.
Judges said the onus was on the Chief Constable to consider whether to complete and publish a thematic report, with independent officers appointed to decide how to respond to the expectation.
Proceedings were brought by Edward Barnard, whose 13-year-old brother Patrick was among four people killed in a St Patrick's Day bombing at the Hillcrest Bar in Dungannon in March, 1976.
Five years later Dungannon UVF member Garnet James Busby received a life sentence after admitting his role in the no-warning attack and other terrorist offences.
The murder gang based at a farm in Glenanne, Co Armagh allegedly contained members of the Royal Ulster Constabulary and the Ulster Defence Regiment.
Up to 120 murders in nearly 90 incidents in Mid Ulster and Irish border areas are under scrutiny.
They include outrages such as the 1975 Miami Showband Massacre, where three members of the popular group were taken from their tour bus and shot dead on a country road in Banbridge, County Down, and the Step Inn pub bombing in Keady a year later, which claimed the lives of two Catholics.
It has also been linked to the murder of 33 people, including a pregnant woman, in the 1974 Dublin and Monaghan bombings.
A draft HET report into alleged security force collaboration with the killers was said to have been 80% finalised before being shelved.
In a third case, the Court of Appeal ruled in September that interrogation techniques used against the so-called Hooded Men during internment in Northern Ireland would be torture if deployed today.
Senior judges also held that the group had a legitimate expectation police would further investigate claims their treatment in 1971 was sanctioned by the British Government.
Although Sir Declan formally declined to grant leave to appeal in both the Hooded Men and Glenanne cases, he indicated that it was because permission was being given in proceedings relating to the death of Mrs Smyth.
"We are going to leave it to the Supreme Court to decide whether to take these cases in as well," he added.
Lawyers for the PSNI will now consider if they should petition directly to have all three legacy cases examined.
Outside court a solicitor for some of the victims claimed they had received high-level assurances no such applications to appeal would be mounted.
Kevin Winters said: "It is with regret that those we represent are once again rebuffed and let down by the PSNI in its application to seek leave to apply to the UK Supreme Court to challenge three important judgments of the Court of Appeal in relation to the legacy of the conflict.
"There can be no progress for relatives of victims and survivors as long as state agencies including the PSNI seek to challenge the judgments of our Court of Appeal."