Authorities named the live-in boyfriend of the mother of a 6-year-old girl found hanged and sexually assaulted as the primary suspect on Thursday.

Kevin Wayne Anders was arrested late Wednesday on charges of unlawful possession of child pornography after an analysis of computer files revealed pornography, said Chief Deputy Mike Cox of the Navarro County Sheriff's Office. Anders is being held on a $100,000 bond.

Hanna Mack was discovered Monday by her mother, Dana, hanging in the garage with a rope around her neck in Navarro Mills Lake, about 65 miles south of Dallas, and there were signs that she had been sexually abused, police said.

"I just touched her arm and I wanted to get her down so bad," Dana Mack told

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"I will confirm that the hanging and sexual assault were part of this scenario," Navarro County Sheriff's Chief Deputy Mike Cox said.

Cox said several people had been interviewed and no one has been ruled out as a suspect.

"We don't want to do anything that would compromise a successful prosecution of this case," Cox said Wednesday before abruptly ending a brief news conference.

In a letter to the sheriff's department, Navarro County Judge Vicki Gray said an autopsy of the body showed "a multitude of events that together caused the death of this child."

The first-grader's body was found in a garage behind her home early Monday.

"I'm just concerned about the kids out there," said Harold Hocutt, 75, a neighbor who knows the girl's family. "Little girls. Little boys. It's just something you don't forget. Every time I drive by [Hannah's house], I cry."

Police asked state caseworkers not to say whether Hanna's family had been investigated by child welfare officers, said Marissa Gonzales, a spokeswoman for the Texas Department of Family and Protective Services.

"I wish I could punish this person myself," Dana Mack told

The Associated Press contributed to this report.