A Fredericksburg, Va., woman was sentenced yesterday to five years in prison for involuntary manslaughter in the death of an 18-month-old boy for whom she was baby-sitting.

The sentence -- the maximum penalty for the offense in Virginia -- was imposed by Circuit Court Judge John A. Jamison on Jerussia Lucas, 27, who was convicted by a jury on Sept. 6.

According to evidence presented at the trial, Lucas shook 18-month-old Kevin Conner's head on the floor when she was unable to stop him from crying. According to testimony, Lucas became frightened when the baby's eyes rolled back in his head and she called a neighbor, who called a resue squad.

The baby was first taken to a Fredericksburg hospital, where he was found to have a 6 1/2-inch skull fracture, and then was moved to D.C. Children's Hospital, where he died.

Medical evidence given at the trial showed that the baby had sustained a blow that was equivalent in force to a fall from the second floor of a building.

"We think she just went into a rage," said M. R. Reamy, Spotsylvania County commonwealth's attorney.

"We have never had a case where the child was killed (as result of abuse) in this county," he added.