ADA, Okla. -- A Pontotoc County jury had convicted an Oklahoma couple for killing their foster son and abusing the boy and his older brother.

James Rex Clark, 67, and his 61-year-old wife Rebecca Clark of Seminole County, were found guilty of first-degree murder in the 2006 death of Colton Clark, their nine-year-old nephew and foster son.

Colton's body has never been found.

The couple faces the prospect of life in prison at their formal sentencing on December 11.