A sensational homicide case rocks Boston in the series' two-hour, sixth-season opener. The defendant is a charismatic state senator, who's charged with killing the man purported to be his wife's lover. Pretrial drama centers on the accounts of two key witnesses: the politician's intransigent spouse and his reticent teenage daughter. Later, courtroom skirmishes are interwoven with the sometimes contentious strategizing of prosecutor Helen Gamble and her associate, Alan Lowe; and squabbling on the defense team, led by Ellenor