A Belfast resident has won a case at the UK's highest court over the failure of the PSNI to prevent union flag protests.
Five Supreme Court justices in London ruled unanimously in favour of the unnamed resident, announcing that the PSNI did have the legal power to stop the parades.
Mass loyalist demonstrations, some of which descended into serious violence, were staged across Northern Ireland in opposition to Belfast City Council's decision to limit the number of days the union flag flew over City Hall.
In April 2014, a judge at the High Court in Belfast ruled in favour of the resident of the nationalist Short Strand area of east Belfast, who claimed the police's failure to stop unnotified loyalist marches past his home between December 2012 and February 2013 breached his right to privacy and family life.
Later that year, appeal judges overturned the ruling following a challenge by the PSNI.
The resident then took his case to the British Supreme Court.
Today, the justices said the PSNI had "misconstrued" its legal powers to stop parades passing through or adjacent to the Short Strand area.
As permission for the loyalist marches was not sought from the Parades Commission adjudication body, the events were not lawful.
In ruling in favour of the resident, referred to only as DB, the judge at the High Court in Belfast found that police had not properly understood their powers to intervene in the protests.
But three appeal judges, among them Northern Ireland's Lord Chief Justice Sir Declan Morgan, came to a different conclusion and allowed the PSNI's appeal against the judgment.
The PSNI had argued that the original ruling regarding its handling of union flag protests would have placed major constraints on how it polices future parades and demonstrations in the North.
They said commanders' decisions to contain the protests and pursue arrests and charges at a later date fell within their discretionary powers.
But Lord Kerr, giving the ruling of the Supreme Court, concluded: "I would reverse the decision of the Court of Appeal and make a declaration that, in their handling of the flags protest in Belfast during the months of December and January, PSNI misconstrued their legal powers to stop parades passing through or adjacent to the Short Strand area."