BOSTON (CBS) – She was found dead in a river, but police have still not said how Celina Cass died.

An autopsy performed Tuesday did not determine how the 11-year-old died, but WBZ-TV has learned her body was found wrapped in blankets.

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In another development Wednesday, Cass’ stepfather, Wendell Noyes, checked himself into a mental health facility in Concord. Investigators also seized a silver pickup truck that neighbors say was typically driven by Noyes.

Authorities have appeared to increase their focus on Celina’s home, which she shared with her mother, stepfather, sister and a man not related to Celina.

Celina’s biological father, Adam Laro, says he never noticed anything strange at the house, until the last time he visited her.

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He says recently Celina and her sister were sleeping in the basement.

“It seems odd to me, very odd. Here they had two beautiful rooms and a nice place to live all of a sudden things got changed by certain people who I won’t name,” says Laro.

“Now all of a sudden they’re staying on an air mattress on the cellar floor, to me it’s kind of crazy.”

The two men living in Celina’s home have criminal records.

Noyes was arrested in 2003 for breaking into an ex-girlfriend’s home and threatening her. He was committed to a psychiatric hospital for paranoid schizophrenia.

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The other man in the house, 23-year-old Kevin Mullaney, is the son of Celina’s mother’s ex-boyfriend. Mullaney has served time for stealing cars.