Purposes of cross-examination include impeachment of the defense witness or, if the testimony turns out to be favorable to the prosecutor's case, underscoring the testimony. Pretrial preparation is advised. For example, one paper recommends that such sources as the defendant's prior criminal records, probation reports, and booking information be studied. The paper also suggests how the prosecutor may use the voir dire process and the opening statement to orient the jury as to what may or may not occur during cross-examination. Helpful cross-examination strategies are suggested. One paper suggests that strategies should vary according to the type of the defendant or the witness. Possible types include the loquacious defendant, the honest witness, and the clergyman as a witness. For example, when cross-examining a clergyman testifying about the defendant's character, the prosecutor should point out that it is the clergyman's life's work to protect the souls of the people belonging to the parish. Advice on when not to cross-examine is also given. For example, it may be better not to cross-examine a strong witness. Relevant case law is discussed.