Almost a decade later, a man is charged with killing 5-year-old Fitchburg boy

The man charged with murder in the death of 5-year-old Jeremiah Oliver, whose body was found in a suitcase beside a Massachusetts highway in 2014, pleaded not guilty at his arraignment on Thursday and was held without bail.

Alberto Sierra Jr., 32, was the former boyfriend of Jeremiah's mother and was arrested on Wednesday, according to the office of Worcester District Attorney Joseph Early Jr.

Prosecutors did not say what led to Sierra's arrest. Messages seeking comment were left with his attorney.

Jeremiah’s body was found in April 2014 along Interstate 190 in Sterling, about an hour west of Boston, and not far from his family's home in Fitchburg. But the boy was last seen alive in September 2013, and was not reported missing until December of that year.

The case has weighed heavily on the mind of Fitchburg Police Chief Ernest Martineau, who was involved in the intitial investigation.

“This case rocked the conscience of the city of Fitchburg,” he said outside Worcester Superior Court. “At one point, we were Jeremiah’s family, 45,000 residents in the city, and we are here today, beginning the process of healing.”

The case reverberated across the state, with even then-Gov. Deval Patrick saying he was trying to “keep my own rage in check.” The boy's death also led to three employees of the state's child welfare agency getting fired, and spurred reforms at the agency.

Jeremiah's family was being supervised by the state Department of Children and Families. Even before his body was discovered, an investigation found that a social worker with the child welfare agency went months without visiting the family's home — despite reports of abuse and neglect.

The death was not ruled a homicide until February of 2016 when an autopsy by the state medical examiner said that he died of “homicidal violence of undetermined” causes.

Sierra was convicted in 2017 of assaulting Jeremiah's mother and siblings and sentenced to up to seven years in prison. He was not currently incarcerated when he was arrested Wednesday, the district attorney's office said.

Jeremiah's mother, Elsa Oliver, also pleaded guilty in 2017 to assault and battery and reckless endangerment in connection with her other two children and was sentenced to more than seven years in prison.

Prosecutors dropped charges against both of them in connection with Jeremiah's disappearance and alleged abuse in order to avoid possible double jeopardy claims, prosecutors said at the time.

Sierra is also charged with disinterring a body. He is scheduled back on court on May 25. The investigation into the death is ongoing, prosecutors said.