FITCHBURG, Mass. — A Massachusetts mother and her boyfriend are due in court for hearings as police and relatives continue searching for her 5-year-old son.

Elsa Oliver of Fitchburg is charged with reckless endangerment of a child and being an accessory after the fact. Her boyfriend, Alberto Sierra, is charged with assault and battery with a dangerous weapon and assault and battery on a child. They’ve pleaded not guilty.

Oliver’s son, Jeremiah, was last seen by relatives in September and is feared dead. Authorities learned about the boy’s disappearance only recently.

Oliver and Sierra are due in Fitchburg District Court Tuesday. Both are being held without bail.

Jeremiah’s father, Jose Oliver of New Britain, Conn., searched for his son Saturday in Fitchburg with relatives and friends, but didn’t find any clues.