CAMBRIDGE, Mass. (AP) _ A few months after Louise Woodward moved in, the Eappen family and their English au pair were at a crossroads.

Woodward appeared capable and got along well with 2 1/2-year-old Brendan and baby Matthew. But the little things _ late nights, long phone calls during work _ kept piling up, like the dirty diapers Deborah Eappen wanted the 18-year-old to throw out more often.

Finally, last January, the Eappens gave her a choice: Agree to a written set of guidelines or leave. Woodward agreed.

Five days later, 9-month-old Matthew Eappen lay dying on a hospital respirator, his brain oozing through a crack in his skull the length of a newborn's foot. Woodward was arrested the next day. Matthew died Feb. 9.

Jury selection in her first-degree murder trial was to begin today. If convicted, she would be sentenced to life in prison, with no parole.

The case has resonated among parents who entrust their children to strangers on the strength of a few references and faith in human nature.

Au pairs are college-age women who travel to the United States and work up to 45 hours a week in exchange for room, board and a stipend. Au pair agencies have been criticized before for inadequate screening and training.

In England, some questioned the charge's severity and the denial of bail for Woodward, a young woman with no criminal past. ``All we've ever asked for is for Louise to be treated fairly and that she has a fair trial,'' her father, builder Gary Woodward, told ITV television.

Physicians said someone shook Matthew hard for at least a minute, then cracked his head against something with the force of a two-story fall. The autopsy also showed an earlier wrist fracture. Prosecutors were expected to argue it was caused by previous abuse by Woodward.

Police said Woodward told them she had been frustrated all morning by Matthew's crying, was a ``little rough'' with him after his morning bath and may have dropped him on a towel.

She said she didn't notice anything wrong with the baby until he appeared to have stopped breathing in his crib, and she called emergency workers.

Woodward denied doing anything that could have killed Matthew. Now 19, she said she only shook him when she panicked while trying to revive him after some kind of convulsion. She denied telling police the baby's head hit the floor.

She said she and the two children were alone at Deborah and Sunil Eappens' home in suburban Newton while the parents, both physicians, were at work.

The agency that sponsored Woodward, EF Au Pair of Cambridge, has hired her defense team.

The agency also paid for the defense of another au pair, Olivia Riner, against charges that she burned to death a New York baby in 1992. The Swiss citizen was acquitted.

In 1994, au pair Anna-Corina Peeze of the Netherlands was charged with shaking a baby to death in Virginia. She pleaded guilty to a lesser charge in a case that prompted widespread debate on U.S. regulation of European nannies.

The Eappens held a birthday party for Matthew in May, mired in grief as the case goes forward, said family friend Matthew McCue.

``They can never get beyond what happened to Matthew,'' he said.