Though Mariah has not been found, officials say evidence gathered during the investigation indicates she may be dead.
The Onslow County Sheriff's Office and the Federal Bureau of Investigation took 32-year-old Earl Kimrey into custody on Friday.
The arrest warrant issued for Kimrey said he obstructed justice by "removing Mariah Woods' body from the scene of her death and did hide Mariah Woods' death and body, knowing that Mariah Woods died from unnatural causes". By the next morning, Mariah was missing.
He was being held in the Onslow County Detention Center with bail set at $1,010,000.
Saturday afternoon, officials said they were still searching for Mariah Woods, but believed she was dead.
Earlier on Friday FBI forensic teams were testing "items of interest" in their desperate search for Mariah.
Mariah believed to be dead; mother's live-in boyfriend arrested
In all, 730 volunteers joined law enforcement personnel in the search on Friday. "This is my angel", the mother said. Mariah has been missing since Sunday night when her mother put her to bed.
A missing 3-year-old North Carolina girl is believed to be dead and her mother's live-in boyfriend faces charges in connection with her disappearance, authorities said. "Someone just walked right up in there, grabbed the 3-year-old out of the bed, and she didn't cry, she didn't scream?" he said.
Photos of Mariah Kay Woods.
As the search for Mariah intensified, questions swirled about the story told by Mariah's caretakers. "Four people in the house, two adults and two kids, someone just comes up and snatches the baby and walks out?"
Authorities say the man charged in the disappearance of a young North Carolina girl is the boyfriend of the child's mother.
Kristy, who this week disabled her Facebook account after posting the missing person's appeal for her daughter, claimed that Mariah was taken by a stranger. "I'd give anything." WATCH: "Raw video of emotional interview with Mariah's biological father She is described as a white female standing about 2' 9" tall and weighing around 30 pounds. "Please, bring her back".
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