The former prosecutor in the "Twilight Zone" case filed a $7-million lawsuit against the county and several high-ranking officials of the district attorney's office, claiming that they have launched a campaign to discredit him and have "tainted" future investigations in which he may participate "to gain an unfair political advantage." Deputy Dist. Atty. Gary Kesselman's federal court suit claims that he was reassigned from the special trials division of the office to the complaint division and publicly accused of secreting evidence after he refused to testify that he had been told by a prosecution witness that director John Landis, a key defendant in the case, had once said he expected to go to jail for hiring two children eventually killed on the movie set. Named as defendants are Lea D'Agostino, who succeeded Kesselman as prosecutor on the case, Chief Deputy Dist. Atty. Gilbert Garcetti and Richard Hecht, director of central operations.