FITCHBURG -- Three people were arraigned Monday on charges they lied to investigators and a grand jury about the Jeremiah Oliver case, including the brother of the boy's mother's boyfriend.

Investigators believe Christian Sierra, 21, of Fitchburg, lied to the grand jury about phone calls he made in December to his brother, Alberto Sierra, during the investigation, which may have slowed down or misled the investigation, according to court documents at Fitchburg District Court, where the arraignment was held.

Jeremiah Oliver, 5, was last seen by relatives Sept. 14. His mother, Elsa Oliver, and her boyfriend, Alberto Sierra, are still in police custody and have not said anything about the whereabouts of the boy, who is presumed dead.

Also arraigned Monday on similar accusations were Ashley Cormier, 24, of Fitchburg, and Caily Thibault, 23, of Fitchburg, both of whom are identified as friends of Elsa Oliver and Alberto Sierra.

Thibault and Christian Sierra are in a romantic relationship and live together. They told police they share a cellphone.

Court documents signed by a Massachusetts State Police trooper said phone records show they committed perjury in front of the grand jury. All three were charged with intimidating a witness, juror, police or court official.

Reports from the state police say that on Dec. 16, in front of a grand jury, Christian Sierra denied having contact with his brother after he left his apartment on Dec. 13, but phone records show the two exchanged 10 phone calls in the hour and a half after he left.

Cormier was reportedly with Elsa Oliver almost the entire day on Dec. 13, when Elsa Oliver was questioned in court. Cormier claimed she made no phone calls during their time in court, but records show she made several between 9 a.

Christian Sierra, 21, of Fitchburg, back, leaves Fitchburg District Court with his parents Monday after his arraignment on charges that he lied to the
Christian Sierra, 21, of Fitchburg, back, leaves Fitchburg District Court with his parents Monday after his arraignment on charges that he lied to the grand jury investigating the case of Jeremiah Oliver, 5, who is presumed dead.
m. and noon, including five to Alberto Sierra.

It is also alleged that Cormier became confrontational with workers from the state Department of Children and Families when they attempted to speak to Elsa Oliver at her home on Dec. 13. The workers felt they were in physical danger.

A witness told police Thibault threatened Elsa Oliver with violence on Dec. 13 in order to get her to go to Fitchburg District Court.

Elsa Oliver, Cormier, Thibault, and both Sierra brothers were seen meeting together at Cumberland Farms in the Cleghorn Neighborhood of Fitchburg after Elsa Oliver's court appearance on Dec. 13. Thibault claimed she made no phone calls on Dec. 13, but security footage shows her speaking on a cellphone that had belonged to her deceased father that she did not tell the grand jury she regularly uses.

Cormier and Thibault are each being held on $2,500 cash bail. Christian Sierra's parents put up his bail, which was set at $2,000 cash or $20,000 collateral, Monday about 4 p.m.

All three are scheduled to return to Fitchburg District Court on April 15.

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