There was nothing amiss when a social worker visited the family in Apartment S7 in Morrisville, Pa., on Feb. 5. When she went back to the unit on Monday for a wellness check on the eight family members who lived there, no one answered her knock on the door, and a maintenance worker called the police, according to a criminal affidavit.

Inside, the apartment was in disarray, according to the affidavit, which was dated Tuesday. Broken glass was strewn around, and furniture was turned over, it said. And in a back bedroom, five people, including three children, were found dead, their bodies sprawled across a bed or on the floor. A woman and a teenager were found alive, “disoriented” on a bed, it said.

On Tuesday, the woman, Shana S. Decree, 45, and her daughter Dominique K. Decree, 19, were each charged with five counts of criminal homicide and one count of conspiracy for the deaths of their relatives, the authorities said. According to the affidavit, Shana Decree told the police all of the apartment’s occupants had spoken about suicide and “wanted to die.”

Matthew D. Weintraub, the Bucks County district attorney, said the two women were charged in the deaths of Shana Decree’s children, Naa’Irah Smith, 25, and Damon Decree Jr., 13. They were also charged with the deaths of Shana Decree’s sister, Jamilla Campbell, 42, and Ms. Campbell’s daughters, Erika and Imani Allen, 9-year-old twins.