The girls were last seen alive on Monday evening with their mom, 36-year-old Tinessa Hogan, who investigators say had been offering baptisms in the canal.
"She was in the water swimming, she had a bible and she told me to come here," neighbor Lawana Johnson told CBS Miami. "I said, 'Why?' She said she wanted to baptize me. She say God told her, I say 'God didn't tell you anything."
"I don't know what her personal beliefs are," Lt. Mike Bigwood responded to questions about Hogan. "We have information... that she was in the canal, that she was offering to baptize people in the neighborhood. That is an angle an angle we are exploring."
Police were also elusive about Hogan's status or whereabouts, citing "legal reasons" for not elaborating further.
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"She is not under arrest at this point. And the community is not in any harms way at this point," Bigwood sidestepped. "She is not home. She is not out in the community right this second."
He added: "I'd like to clarify that 'in custody' is not 'under arrest'."
Nor could he confirm if she was placed under the 72-hour psychiatric hold allowed under the Baker Act.
"At this point I would classify it as two suspicious deaths. We are definitely treating it as if it was a criminal investigation, but we treat all suspicious deaths pretty much in the same manner."
Police did confirm to the Sun Sentinel however that Hogan was taken away in an ambulance on Tuesday about four hours after Destiny's body was found, exhibiting "alarming" behavior. One witness told the publication she was screaming bible verses and shouting "I am God" and "I am the Devil" as she was taken away.
"Please if you know the family, if you know the children, if you are familiar with the relationship, if you are familiar with any churches or organizations that the family may be a part of, please call us," Bigwood pleaded. "We desperately need to know what these relationships are."
Destiny was pulled from the canal wearing blue jean shorts and a grey shirt with the word "dance" in rainbow colors at 12:10 PM on Tuesday. Her sister was found nine hours later, a half mile away in the same stretch of water, wearing a tan T-shirt and pajama bottoms with flowers. Neither had been reported missing.
Autopsies on both girls were completed on Wednesday, but the cause of death has not yet been revealed. There were no signs of trauma on either body.
The girls' father has been estranged from the family for years.