Northern Ireland police released Sinn Fein leader Gerry Adams after four days of questioning over the 1972 abduction and murder of Jean McConville. (Reuters)

— A week after his mother was dragged from his arms and murdered, 11-year-old Michael McConville was himself abducted and warned to keep quiet.
Forty-two years later, he says he’s never named the Irish Republican Army members who killed his mother because he fears doing so could leave his children without a father.

But one other name associated with the case is now known to the world: Gerry Adams.

When the Sinn Fein leader was arrested last week on suspicion of ordering Jean McConville’s murder in 1972, the furious reaction and near-breakdown of a critical power-sharing arrangement showed just how vulnerable Northern Ireland remains to assaults from its past.

In many places, it would be too late to prosecute a murder case gone cold, four decades after McConville’s body was secretly buried on a lonely stretch of Irish beach. But in Northern Ireland, where the ghosts of “the Troubles” continue to haunt the fragile peace, it may be too soon.

Despite 16 years of relative calm ushered in by the U.S.-brokered Good Friday Agreement, one of the most successful peace accords of modern times, trust between the unionist and republican camps runs remarkably thin, with especially little agreement about how to reckon with the legacy of 3,600 deaths over three decades of violence known as the Troubles. Both sides warn of dark plots to bring the instability back.

Michael McConville's mother was killed when he was 11, 42 years ago. Here, he shows the only photo he has of her plus a photo of himself from childhood. (Griff Witte/The Washington Post)

Although Adams was released Sunday, few doubt where the standoff would have led had he been charged.

“There would have been riots,” said Alfie Butler, 58, who lost his niece and her daughter in a 1993 bombing. “It’s fine to talk about progress in Northern Ireland. But the paramilitaries haven’t gone away. The gangsters are still here, on both sides.”

Butler spoke from a pub on Shankill Road, a unionist stronghold that is within sight of the gleaming new office buildings and trendy restaurants of Belfast’s city center but is, in many ways, stuck in an older, far gloomier time. Like its republican mirror image, Falls Road, Shankill is dominated by boarded-up businesses, low-rent housing and memorials to the dead.

The latter have become tourist attractions, must-see stops for photo-snapping travelers from around the world. But for residents, the grievances still run deep, and the memorials are well tended with fresh flowers to honor brothers, sons and other family members who were lost to the fighting.

Tensions still high

Beginning in the late 1960s, Shankill and Falls roads were the front lines in a guerrilla war pitting Northern Ireland’s Protestant majority and its backers in the British army against the Catholic minority, which sought to secede from the United Kingdom and join Ireland.

To this day, neighborhoods and even individual streets are partitioned, with Union Jacks and Irish tricolors demarcating the boundaries between unionist and republican. Schools, pubs and soccer allegiances are similarly divided along sectarian lines.

Since 1998, peace has reigned, and Northern Ireland has prospered. But there has never been agreement on how to address the crimes of the past, particularly the many unsolved killings.

When Adams was arrested, police cited new evidence from a Boston College oral history project in which former IRA members apparently named Adams in connection with the McConville case. Police commanders said that they were simply following the evidence and that it led to Adams, who has strenuously denied any involvement in McConville’s death.

But Sinn Fein ascribed darker motives, with senior leader Martin McGuinness blaming “a cabal” within the police force that has “a negative and destructive agenda to both the peace process and to Sinn Fein.” McGuinness suggested his party would withdraw support for the police and launch protests if charges against Adams went forward.

The threat hung heavily in Northern Ireland, where Sinn Fein long served as the IRA’s political wing and remains the most potent force in the republican movement. Although the group has disavowed violence, the prospect of Sinn Fein activists massing in the streets while accusing the police of treachery set Belfast on edge.

In an interview, Peter Robinson, the unionist leader of the Northern Ireland assembly, said Sinn Fein’s message was unmistakable: “Unless the police backed away from charging Mr. Adams, Sinn Fein would bring the house down on us all.”

Robinson said if Sinn Fein had made good on its threat, he had one of his own. He would have tried to force the party out of Northern Ireland’s unity government, an act that would have escalated tensions.

Trying to move forward

In the end, Adams wasn’t charged, and instead was freed Sunday night after four days in custody. The following evening, Sinn Fein gave him a rapturous welcome back, with 700 party activists packing a Belfast ballroom to cheer his return.

While Sinn Fein had accused the police of political meddling by arresting Adams just weeks before European and local elections, the impact seemed only to have galvanized his backers, who swayed to the rhythms of protest ballads written decades ago from bleak prison cells. For a party built on defiance, Adams’s freedom was fresh evidence that Sinn Fein could still stand up to its enemies.

“Those opposed to the peace process tried and failed once again,” IRA veteran Bobby Storey shouted to deafening applause. “The stronger we get, the harder they will try.”

Smiling broadly and pausing to joke with the crowd, Adams pronounced his arrest “a sham” but was more conciliatory than McGuinness had been, saying the police had his support. He also pledged to “help all of the families” of those killed during the Troubles.

“Legacy issues should be dealt with by an independent, international body,” Adams said in an interview the following day. “You couldn’t expect Sinn Fein to set up a process of truth and reconciliation. We would be seen as partisan. So we need to go for best practices internationally.”

Robinson, the unionist leader, dismissed that idea, saying that Northern Ireland’s own justice system is up to the task and that “a murder is a murder whether it’s committed in this decade or any previous decade.”

But for Michael McConville, the prospect of winning justice for his mother’s murder feels remote.

Now 52, the soft-spoken McCon­ville vividly remembers the night in 1972 when 10 IRA members burst into his family’s home and dragged his mother away as her children screamed. The IRA has said it suspected Jean McConville of being an informant for the British, although a later investigation turned up no evidence. Thirty-seven years old at the time of her death, she would have turned 80 Wednesday.

Michael McConville said he recognized many of his mother’s abductors from the neighborhood — and has seen them around town in the years since. But he’s never revealed the names, fearing the consequences for his family if he does.

“I know the hurt and the pain that I’ve gone through, and I wouldn’t want that for anyone else,” he said. “Growing up in the Troubles, I’ve seen an awful lot of people getting killed. I’m hoping — and my whole family is hoping — that we don’t go back to those dark days.”

Karla Adam in London contributed to this report.