An 18-year-old Oxon Hill woman has been arrested by Prince George's County police and charged with first degree murder after the body of her 2-month-old son was found in a patch of woods near her home.

Police said the infant, David Anthony Newton, son of Edith Yvonne Newton, was smothered last Friday and his body was kept in the trunk of the mother's car for several days before it was placed in the woods.

The baby apparently was killed to keep him from crying, police said.

Newton is being held in the county detention center in Upper Marlboro, and is scheduled to go before a judge today for a bond hearing.

"From what we can learn as far as the motive there was apparently . . . a fit of rage because the baby was crying," said police spokesman Robert Law. He said there had been no earlier reports of child abuse or other complaints involving the child.

Neighbor Jo Ann Francis, who described Newton as kind and shy, said the stable, well-kept neighborhood was shocked. Newton, she said, "was so sweet . . . I'm flabbergasted."

Francis, a grocery clerk who has lived across the street from Newton and her parents since they moved to the neighborhood 12 years ago, said the family kept to themselves.

"We didn't even know she was pregnant. She sort of hid it," Francis said. "They stayed inside."

Newton, an only child, was unemployed and not in school, police said. Records show she attended public schools through the ninth grade, and switched to a private school.

The investigation began Wednesday with an anonymous call to the county Department of Social Services, hinting that the baby might be missing. A social worker then went out to the brick split-level on Owens Road to talk to Newton.

After interviewing Newton, the worker contacted police. When police first questioned Newton, she said her little boy was missing, police said.

Police said the baby apparently died in the basement of the Newton home after a hand was held over his mouth. His body stayed in the trunk of Newton's blue compact car for three days, until Monday night, police said.

On Wednesday, police said, Newton accompanied them to the body, past a day-care center, a fruit stand and a mile of well-kept homes, to a wooded area next to an apartment complex. She was subsequently charged in the infant's death.

Newton had told her parents the child was staying with relatives, according to a source close to the investigation. A man answering the door at the Newton home yesterday declined to talk about the case.

Experts said yesterday that the charges are not uncommon, with 2,000 to 4,000 fatalities reported nationally as a result of abuse. The problem is particularly serious among teen-age parents.

"They're barely more than children themselves," said Christine Felker, assistant to the director of the county Department of Social Services. "The baby cries through the night, the mother gets tired, and they have no resources to draw on."