A man believed to be the father of "Baby Grace," a 2-year-old girl whose body washed ashore in Texas, said in an interview broadcast Thursday that the girl's mother loved her, and he didn't believe she was capable of harming the little girl.

The girl's mother, Kimberly Dawn Trenor, and stepfather, Royce Clyde Zeigler II, were arrested Saturday and charged with injury to a child and tampering with evidence. According to court documents, Trenor, 19, told police she and her husband killed the girl in July and hid her body in a shed before dumping it in Galveston Bay.

• Click here for photos of Riley Ann Sawyers.

• Lawyer: Stepdad Beat to Death 'Baby Grace' for Not Saying 'Please,' 'Yes, Sir'

While DNA tests are pending, authorities say they are fairly confident the girl nicknamed "Baby Grace" after washing ashore last month is that of Riley Ann Sawyers. Riley's father, Robert Sawyers, said Trenor loved their daughter.

"No, I never thought she could do anything like this," Sawyers said in an interview broadcast Thursday on NBC's "Today" show.

"I mean, she loved Riley. ... You can't not love that little girl the first time you see her, you know. It's heart wrenching to think she might have done this to such a beautiful little girl," said Sawyers, 20, of Mentor, Ohio.

Sawyers was never married to Trenor but the high school sweethearts lived with their daughter in his parents' Ohio home for about two years. He was charged with domestic violence against Trenor in March, and the two split up. The charge was reduced to disorderly conduct.

Sawyers said Thursday that he never hit Trenor and said the charge stemmed from "an argument that got blown out of proportion."

Trenor moved with her daughter from Ohio to Texas in June to be with Zeigler. Sawyers said Trenor didn't give him a reason for ending their relationship.

"She just told me one day that she just didn't want to be together anymore," he said. "Gave me back the ring that I gave her for our engagement and just got distant after that."

A teary Sawyers said he wanted his daughter to be remembered as "a beautiful, loving little girl. I mean, there's nothing more else to her than that. She's beautiful, loving, and touches your heart the second you meet her."