An Ohio couple is facing charges after they returned their 9-year-old adoptive son to child welfare authorities.

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Cleveland Cox, 49, and Lisa Cox, 52, pleaded not guilty Wednesday in a Butler County court to charges of nonsupport of dependents.

The Coxes claim that the boy, who they had raised since infancy, was displaying aggressive behavior and threatened them with a knife.

An attorney appointed on behalf of the boy told the judge that it's the parents' responsibility to find help for their son.

Butler County prosecutor Michael Gmoser explained that adoptive parents cannot simply bring a child back.

"Children are like that box of chocolates. When they are born into your life - whether by adoption or by natural means - you really never know what you're going to get. But you have the responsibility, especially if you have the means, to care for them up until adulthood," he said.

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