Evan Schaeffer at illinoistrialpractice.com has this post:
In the new book, Your Witness: Lessons on Cross-Examination, there is a chapter titled "Cross-Examining the Liar" by Chicago lawyer Dan Webb.
Webb, who has cross-examined scores of liars during his long career, begins the chapter by describing the two requirements that must be present before you even begin to think about trying to take on a liar at trial–
- First, you must be certain that you can establish that the witness has a "clear-cut motive to fabricate that the jury will understand";
- Second, you must be certain that you have at least one "clean substantive line of cross-examination" during which you can establish that the witness probably lied.