The mother of a Fitchburg, Massachusetts, boy whose body was discovered in a suitcase off a highway has pleaded guilty to charges of child abuse and child endangerment in connection with her two other children.
The death remains under investigation, and prosecutors retained the right to charge Oliver in the future.
Worcester District Attorney Joseph Early Jr. says his office has dismissed kidnapping and other charges against the 32-year-old Oliver in connection with the disappearance and death of her son Jeremiah Oliver. His death was ruled a homicide.
Oliver's son, Jeremiah, went missing in late 2013.
She was sentenced to seven and a half years in prison-but has already been behind bars for three and a half years and will be credited for that time.
Oliver was sentenced to a total of 7 ½ years for two counts of reckless endangerment of a child and one count of assault and battery, the Worcester District Attorney said.
Oliver, who suffers from bipolar disorder and post-traumatic stress disorder, wanted to plead guilty to spare her surviving children the trauma of going through a trial, her lawyer, Mark Wester, said in court.
Her defense said she pleaded guilty because she didn't want to subject her children to a trial of any kind. She did not speak in court other than to enter her plea.
That investigation remains active and ongoing and is now being investigated by the State Police Detectives assigned to the Worcester County District Attorney's Office and Fitchburg Police.
Sierra pleaded guilty to three counts of assault and battery with a unsafe weapon, two counts of assault and battery, and two counts of reckless endangerment of a child for assaulting the surviving children and Oliver. Prosecutors also dismissed all charges Sierra had faced relating to Jeremiah.
Jeremiah's two siblings, one boy and one girl, were abused by Sierra and Oliver before they were placed in state custody in December 2013.
In the wake of Jeremiah's death, three state Department of Children and Families employees were fired for failing to properly oversee his care, and Olga Roche, the department's commissioner, resigned.