Sinn Féin President Gerry Adams will not be prosecuted in connection with the IRA murder of Belfast mother-of-10 Jean McConville.
Northern Ireland's Public Prosecution Service said Mr Adams and six others, among them Sinn Féin's northern chairman Bobby Storey, will not face charges.
The PPS made the announcement after reviewing police files on the seven individuals reported to them by detectives investigating the 1972 murder.
Mr Adams was arrested and questioned for four days about the murder last year.
Deputy Director of Public Prosecutions Pamela Atchison said: "We have given careful consideration to the evidence currently available in respect of each of the three men and four women reported and have concluded that it is insufficient to provide a reasonable prospect of obtaining a conviction against any of them for a criminal offence."
Mrs McConville was abducted from the Divis flats in west Belfast by a gang of up to 12 men and women after being wrongly accused of informing to the security forces.
She was interrogated, shot in the back of the head and then secretly buried - becoming one of the "Disappeared" victims of the Troubles.
Her body was not found until 2003, when a storm uncovered her remains on a beach in Co Louth, 80km from her home.
Mr Adams was arrested after voluntarily presenting himself for interview at Antrim police station last April.
He was held and questioned for four days before being released pending the outcome of the prosecution service's assessment of his police file.
Responding to today's announcement, Mr Adams said: "This decision is long overdue. There was never any real basis for questioning me in respect of this case.
"I played no act or part in Jean McConville's death.
"I support the PSNI. But the timing of my arrest showed there remain elements within the PSNI who are against Sinn Féin. But they will not succeed."
Mr Adams added: "I want to encourage anyone with information to assist in the return of the bodies of those people killed and secretly buried by the IRA. I have worked with others towards this and I will continue to do so. I want to thank those who have come forward with such information.
"I am also very conscious of the huge hurt inflicted on the McConville family. The abduction, killing and secret burial of Jean McConville was wrong.
"Sinn Féin has agreed with others, through the Stormont House Agreement, processes for addressing the legacy of the past. We are committed to implementing them."
Speaking to RTÉ Radio’s News at One, former deputy chair of the Northern Ireland Policing Board Denis Bradley said the PPS's decision brings to the fore a number of issues that need to addressed.
“The big one, is that the likelihood of prosecutions is vanishing with every month that goes past and every year that goes past,” he said. “When it comes to legalities and when it comes to prosecutions, the public prosecuting authorities are unlikely to bring cases unless there's a substantial evidence of one kind, either forensic or personal."
Timeline: Jean McConville murder
After four decades of relative inactivity in the murder investigation, the case was invigorated in late 2013 when detectives obtained a number of taped recordings of former IRA members talking about the shooting.
The accounts had been given to researchers compiling an oral archive of the Troubles for Boston College in the US.
After a long legal battle against the college, the PSNI was handed custody of the recordings for potential evidence.
Their seizure prompted a flurry of arrests in 2014, including that of Mr Adams.
Two interviewees in the archive - former IRA commander Brendan Hughes and Old Bailey bomber Dolours Price, both now deceased - claimed Mr Adams ordered the killing of Mrs McConville - allegations the Sinn Féin president vehemently denied.
Upon his release last year, Mr Adams said most of the questions posed by detectives related to the claims made by Hughes and Price on the Boston tapes.
Veteran republican Ivor Bell, 78, from Ramoan Gardens in west Belfast, was charged with aiding and abetting the murder last year on the basis of evidence in the archive, namely a recording prosecutors claim was given by the defendant.
Of the seven files being reviewed by the PPS over the last number of months all but one related to the events around the murder.
Mr Storey was questioned as part of the wider police investigation, namely about an alleged IRA internal investigation of the killing in the 1990s.
PPS officials outlined the non-prosecution decisions to Mrs McConville's son Michael this morning.
He said the family's quest for justice would go on.
"Those who ordered, planned and carried out this war crime thought that their guilt could disappear along with her body," he said.
"But it has not and we will continue to seek justice for our mother and see those responsible held to account no matter how long it takes."