In 1972, Jean McConville was abducted in front of her children from her home in a Belfast housing project. The 37-year-old, a mother of 10, was then tortured at at least one safe house, before being executed with a single shot in the back of the head. Afterwards, she was secretly buried on a beach in County Louth – it wasn't until 2003 that her mutilated body was found.

On Wednesday Gerry Adams, the leader of the Irish Republican party Sinn Fein was arrested in relation to her murder, according to the Associated Press. In a statement, Sinn Fein said that Adams was simply complying with his previous offer to answer questions about the case. “While I have never disassociated myself from the IRA and I never will," a statement from Adams read, "I am innocent of any part in the abduction, killing or burial of Mrs McConville."

(FILES) Gerry Adams, president of the Irish republican party Sinn Fein, attends the funeral of British veteran left-wing politician Tony Benn at St Margaret's Church in central London on March 27, 2014. Irish republican leader Gerry Adams, head of the Sinn Fein political party, was on April 30, 2014 being questioned over the murder of a woman in 1972, the party said in a statement. "Last month Gerry Adams said he was available to meet the PSNI (Police Service of Northern Ireland) about the Jean McConville case," said a statement on the party's website. AFP PHOTO / CARL COURTCARL COURT/AFP/Getty Images Gerry Adams, president of the Irish republican party Sinn Fein, attends the funeral of British veteran left-wing politician Tony Benn at St Margaret's Church in central London on March 27, 2014 / CARL COURTCARL COURT/AFP/Getty Images

McConville's murder was over 40 years ago, but it still resonates in a Northern Ireland that has struggled to find unity since the Troubles ended.

For decades McConville had been one of the so-called "Disappeared" – 16 men and women who vanished and were widely believed to have been killed and secretly buried by Republican paramilitaries.

McConville had been born a Protestant but converted to Catholicism to marry her husband, Arthur McConville, who had died not long before her murder. In 1999 the IRA argued that they had killed her because she was working as a police informant, though the Police Ombudsman for Northern Ireland said in 2006 they had no evidence that was true. Other accounts suggest she had angered the IRA by offering water to a wounded British soldier.

It was only in 1998 that the Provisional IRA admitted they had killed McConville and some of the others; just a few years before her body was found by chance (authorities had actually given up looking for it). Until recently, no one had been charged in connection with her murder.

The case returned to the spotlight earlier this month when Igor Bell, a 77-year-old former IRA leader, was arrested and charged in connection with the murder. Bell had been one of several former Republican paramilitaries that spoke to Boston College researchers for what was known as the "Belfast Project" – an oral history of the Troubles.

Those involved in the history had been told that their contributions would not be revealed until after their death, but in 2011 a series of subpoenas issued to Boston College by the U.S. Department of Justice on behalf of the United Kingdom changed that. At least two former paramilitary leaders are believed to have implicated Adams in the murder of McConville in their accounts: Brendan Hughes and Dolours Price, both of whom died in recent years.

Adams has always denied being a member of the Provincial IRA, but his account of this has been questioned by a number of journalists. Many people, including McConville's children, believe he was involved in the 1972 murder, perhaps even ordering it personally, and want him to face punishment.

It's Adams' high profile that makes the news Wednesday so shocking – in recent years the Sinn Fein president has been largely accepted as the mainstream political face of Irish Republicanism. The fragile unity seen between Protestants and Catholics in modern Northern Ireland's politics will take a serious hit if his links to a brutal murder could be confirmed. His high profile is also a reason for skepticism about Wednesday's arrest, however: Adams was one of the key signers of the 1998 Good Friday Agreement, which eventually saw the end of the IRA's armed struggle against the British government. A lot of his former allies want to see him punished for that too.