BELFAST, Northern Ireland — Helen McKendry was shopping recently when she spied a former neighbor who she is sure was one of the members of the Irish Republican Army who burst into her home 42 years ago and abducted her mother.

They stared at each other, then moved on.

It has always been that way for Mrs. McKendry and her nine brothers and sisters, the children of Jean McConville, a widow who was wrongly suspected by the I.R.A. of being an informer and dragged out of her living room in front of her family one afternoon in 1972. She was shot in the back of the head and buried on a beach in the Republic of Ireland. Her body was not discovered until 2003, when it was exposed during a storm.

The children grew up and went about their lives knowing the identities of most of the men and women who took their mother, but they never dared go to the police. They say they still see her abductors around town, even on a list of candidates running in local elections this month for Sinn Fein, the former political arm of the I.R.A. and one of Ireland’s main political parties.

But now Mrs. McKendry, 56, the eldest daughter in the family, says she is no longer afraid to speak up. Out of the house when her mother’s abductors came, she says she was told their names by her siblings immediately afterward. She says she gave those names to the police in March, after she became convinced that they were serious about investigating the murder. She has also filed a civil suit against Sinn Fein.