There are basically six devices that witnesses and lawyers use to challenge prosecutors' questions. These include challenging the effectiveness of the procedure designed to protect the witness' constitutional rights; i.e., of immunity; the witness' refusing to answer questions on the ground that the questions are based on illegal eavesdropping (the Gelbard objection); and the witness repeatedly leaving the grand jury chamber to consult with his or her lawyer. Other devices are the witness' claim that he or she has forgotten (which can be used as grounds for perjury in New York); claiming that the contempt prosecution is invalid because the examination was taken in a grand jury that did not have jurisdiction over the putative criminal conduct under investigation; and questioning the prosecutor's fairness. Effective methods of responding to each of these ploys are cited. In preparing for particular witnesses, prosecutors must decide what their goals are, determine the witness' relationship to other witnesses, consider the likely posture of the witness, take advantage of the impact of the subpoena in collecting evidence, and prepare a thorough, accurate synopsis of proof and grand jury agenda with specific areas of inquiry, primary questions, and ancillary questions. It is helpful to draw a mental picture in advance of the contempt or perjury indictment and to spotlight the particular questions which one must plead. The witness must always be advised of his exact situation at the beginning of testimony. During cross examination, the prosecutors must pay great attention to their use of language and psychology, be aware of the record of proceedings in asking questions, establish a tone of fairness, avoid conclusory terms, and resort to repetition in relentlessly pursuing the truth. They must avail themselves of such techniques as refusing to accept ludicrous answers or to be satisfied with feigned answers, using codes in testimony to score points, establishing contrary facts of a lifetime, focusing questions, allowing the witness time to answer, and making the witness agree with questions about the district attorney's fairness or the ridiculousness of an answer. The prosecutor must be aware of the special defenses to compromising circumstances used by government agents and public officials who have accepted benefits. A very extensive set of appendixes contains samples of a synopsis of proof, an agenda, and interrogation, sample grounds for indictment in three separate cases, and indepth analyses of immunity, grand jury practice, and contempt and perjury.