BOSTON (AP) _ One by one they are falling apart, the sensational court cases of the 1980s built on lurid allegations of mass child-molestation at day-care centers.

First it was the McMartin Preschool case in Los Angeles, then the Kelly Michaels case in New Jersey. On Tuesday, a judge in Massachusetts granted a new trial for two women convicted of molesting children eight years ago.

The cases toppled for different reasons. In the latest, the judge said the defendants were denied their right to face their accusers because some of the children were allowed to testify with their backs to the courtroom.

But the common thread was doubt about the veracity of testimony from children who were under pressure to talk to parents, psychiatrists and prosecutors at a time when fears of abuse were sweeping the country.

``There's no doubt that in the mid-'80s, there was national attention paid to child abuse, sexual abuse, spousal abuse. And in the case of child abuse, there was an array of prosecutions based on child reports and many of them went to mush,'' said Arthur Miller, a Harvard Law School professor and legal consultant to ABC's ``Good Morning America.''

Referring to the Massachusetts ruling, he said: ``I think it represents a recognition that you've got to balance the rights of the accused very carefully against the rights of the children not to be inflicted with more trauma.''

Given the perspective of time, judges and juries have questioned whether the children's traumatic recollections of abuse really happened or were planted in their heads by adults.

``Very often people can plant these memories into people's minds,'' said Jack Demick, chairman of psychology at Suffolk University and an expert in developmental psychology.

In the Massachusetts case decided Tuesday, some children spoke of being abused by a clown in a ``magic room,'' while others said they were hung naked from a tree or watched a teacher dismember animals.

Violet Amirault, her daughter Cheryl Amirault LeFave and her son Gerald ``Tooky'' Amirault, were convicted in 1986 and 1987 of sexually molesting 40 boys and girls aged 3 to 6 at their Fells Acres Day School in suburban Malden.

The Amiraults argued that police and prosecution experts planted the allegations through suggestive questioning, but Superior Court Judge Robert A. Barton ordered a new trial only on the issue of facing accusers, following a precedent set by Massachusetts' highest court in April.

Prosecutors immediately said they would appeal.

``It's a very narrow legal technicality and it doesn't affect the basic truth of this case,'' Middlesex County District Attorney Thomas Reilly said.

After more than eight years in prison, the Amirault women could be released after a bail hearing on Thursday. Gerald Amirault, who was tried separately, is waiting for a judge to hear a similar appeal.

``You just can't imagine freedom after being denied it so long,'' Mrs. Amirault said at a prison news conference. ``This is a glorious day for us.''

Although different in the details, the Amirault case resembles other major reversals in day-care abuse cases.

In the McMartin case, Peggy McMartin Buckey and her son, Raymond Buckey, were tried on 52 felony charges after children at their preschool in suburban Los Angeles claimed they were forced to participate in nude games and other sexual activities.

In 1990, seven years after the case began, Mrs. Buckey was acquitted, and the charges against her son were dropped. Juries at two trials had acquitted him on some counts and deadlocked on others.

Margaret Kelly Michaels, meanwhile, was released from prison five years after she was convicted of engaging in ``nude pileups'' with 3- to 5-year-old children at a day-care center where she worked in Maplewood, N.J.

A state appeals court overturned her conviction in 1993, and the New Jersey Supreme Court later harshly criticized investigators for using ``coercive and highly suggestive'' methods in interviewing the children.

Prosecutors decided last December to drop the case against Michaels, saying a retrial was impossible because some witnesses were no longer available and some children and parents wanted nothing to do with a new trial.

Boston lawyers said the same would probably hold true for the Amiraults. Their day care center has been closed since 1984. Many of the children involved are now finishing high school or have left the area.

``It is a shame that the victims and their families are being subjected to this disruption in their lives over this issue,'' said the original prosecutor, Laurence Hardoon, now a private attorney.