NEW : Defense attorney asks witnesses to keep an open mind . NEW : Prosecution offers testimony on Steven Hayes ' prior convictions . NEW : Defense says Hayes has struggled with drug addiction for years . He could face the death penalty for killing a mother and child .
NEW : Defense attorney tells jurors to keep an open mind . NEW : Prosecution offers testimony on Steven Hayes ' prior convictions . NEW : Defense says Hayes has struggled with drug addiction for years . Hayes could face the death penalty for killing a mother and daughters .