He also confessed to having murdered his stepmother , Juanita Smith , who had been missing for several months .
Smith , then 24 , a nephew of the elder McBeths ' , confessed to the crime .
Smith also confessed to having murdered Smith 's stepmother , Juanita Smith , who had been missing for several months .
Smith , then 24 , a nephew of the elder McBeths ' , confessed to the crime .