Raleigh, N.C. — A Harnett County man facing child abuse and child neglect charges after his ex-wife allegedly abused and starved their children for more than a year says he did not know they were being mistreated, although looking back on it, admits that he missed signs of abuse.

"I missed a lot of flags, and I'm going to have to live with that," Brad Thill, a defense contractor from Cameron, said in an interview Thursday on the TV talk show Dr. Phil.

Investigators say his ex-wife, Leslie Tieseler, 37, routinely locked three of their five children in a room and tool chest over a period of 14 months, denied them food, beat them with a wooden spoon and shot them with a BB gun.

Tieseler, who is in jail under a $1 million bond, was arrested in October on three counts of child abuse.

Thill, 38, who had been working in Afghanistan during that 14-month period, was later arrested on three counts each of child abuse and child neglect for failing to report the alleged abuse.

Tiesler has one biological son, and the couple adopted four boys in 2008. The couple divorced in March 2010, and Tiesler moved away with the children, according to Thill. They reconciled, and Thill allowed them to stay with her while he was overseas.

"All I want is for the kids to have a better life, and I thought I was doing the right thing, working, making good money and serving our country," he said on Thursday's show. "I'll never forgive myself."

Thill said that he had been home for a week when the Harnett County Department of Social Services began investigating after a concerned neighbor complained. Social workers left the children in the home for three more weeks before putting them in protective custody, he added.

"I had no knowledge of what my ex-wife was doing to the children," Thill said, even though his 14-year-old adopted son weighed less than 60 pounds. "I started asking questions. She told me one of the children had been treated for anorexia."

There were other signs of problems, too, he said, and for every question he had, Tieseler had an answer.

Clothes in the bedroom smelled like urine and feces, he said, but Tieseler said she was using a toolbox to temporarily store clothes messed up by the boy.

She also said the children had no beds in their bedrooms because they had broken them, Thill said.

He later learned from investigators that the beds were broken because the children were hungry and wanted out of the rooms.

When he pressed his children on the issues, he said, they confirmed what his ex-wife said.

It was after dinner one night during the three weeks after social workers' first visit when he hugged his children goodnight that he realized something was wrong.

"They were afraid to go to her, and she said, 'Don't even think about hugging me,'" he said. "Then, I knew something had been going on in this house. I could see the fear, at that point, in their faces."

When he confronted Tieseler about it, he said, "she would get upset with me and refuse to talk to me, and she would blame me that I left her alone with the children."

Thill's attorney says his client is expected to plead not guilty to the charges during a court appearance next week.

Meanwhile, the five children are still in the custody of social services. Authorities have reported that the three who were abused have all regained a significant amount of weight.

Speaking on the TV show, Thill had a message for them.

"I will get you back home. It's tough right now, but I love you and you will come home," he said. "I will fight tooth and nail. I will work 10 jobs to pay for a legal defense to get you home."