(CNN) Shana Decree pulled her son out of a Pennsylvania school weeks ago. Then with the help of her 19-year-old daughter, she allegedly killed him and four family members, authorities said.

Decree withdrew her son, Damon Decree Jr., 13, from school and didn't follow up with a plan for his education as expected, Superintendent Jason Harris of the Morrisville School District told CNN.

She called the school district two weeks ago, saying her son was not returning to class because she was planning on home schooling him, Harris told CNN affiliate KYW. She was required to provide the superintendent with a home school curriculum, but she never did, he added.

Damon was later found dead in an apartment along with his sister, aunt, and twin cousins. The boy's father, Damon Decree Sr., said he believes his estranged wife and daughter were involved in a cult.

"From my niece, apparently they had dissected into some type of cult that they materialized online," he told CNN affiliate WTVD . "I don't know how, what kind of cult. And they were talking about demons being all around them."

Victims and suspects lived in same apartment

Shana S. Decree, 45, and her daughter, Dominique K. Decree, 19, are accused of killing their relatives at their apartment in Morrisville, north of Philadelphia.

The victims were Shana Decree's other two children, Naa'lrah Smith, 25, and Damon, 13; her sister, Jamilla Campbell, 42, and Campbell's 9-year-old twin daughters, Imani and Erika Allen, authorities said.

All seven lived together in the same apartment.

The mother and daughter have been charged with five counts of homicide and one count of conspiracy, the Bucks County District Attorney's Office said.

A man places flowers at the apartments where the victims were found in Morrisville, Pa.

Surprise visit reveals a horrifying scene

A social worker was conducting a surprise visit Monday when the family was found, according to an affidavit. No one answered the door, so the social worker asked the building's maintenance crew to check the apartment.

Less than 20 minutes later, a maintenance worker called 911. The apartment was in disarray, with the five bodies discovered in one bedroom, the affidavit states. Shana and Dominique Decree were found "disoriented" and taken to a hospital, the document states.

A caseworker with the Bucks County Children and Youth Social Services Agency had visited the family's apartment at least one previous time, according to the affidavit.

"We've been calling and checking and doing everything we needed to do," Decree Sr. told WTVD. "Every time they went, from my perspective at least, they said the kids were safe and it's nothing we could do."

An investigator carries out items from the Robert Morris Apartments in Morrisville, Pa., Tuesday.

Mother and daughter admit to killings

Initially, Shana and Dominique Decree told investigators that three men carried out the killings, according to the affidavit.

But their story changed, and later both women said that they and Shana's sister, Campbell, had killed their family members. "Shana advised that all, including the children, were talking about suicide," the affidavit says.

In separate interviews with police, the women said they choked the others to death, the affidavit says. Dominique Decree's neck had visible injuries, police observed.

Left: Shana Decree RIGHT: Dominique Decree

The cause and manner of the victims' deaths won't be available for several weeks as the coroner waits for toxicology results, authorities said.

Decree Sr. is now grieving the loss of his son, allegedly at the hands of his wife and daughter.

"I don't want them in no insane asylum," he told WTVD. "I want to see them in jail for the rest of their life."

Speaking to reporters Tuesday, Bucks County District Attorney Matthew Weintraub said Shana and Dominique Decree would "be made to pay for their crimes."

"We'll do our best to bring justice to those girls and the other three victims," he said.

It was not immediately clear whether the Decrees have been assigned an attorney.