Expert testimony is the evidentiary cornerstone of toxic tort litigation. Its substance is essential to issues of diagnosis, exposure, and causation—among others—and its effective presentation can impel a jury’s decision in favor of its proponent at trial.
Attacking opposing expert testimony effectively is therefore a fundamental component of trying toxic tort cases successfully. But doing so is not simple; experts in these cases are smart and experienced at handling litigation. They also know their subject matters better than you do. A successful attack on expert testimony at trial requires thoughtful, planned, and strategic deposition questioning of an expert before trial.
Having taken and defended nearly 100 expert depositions as a trial lawyer, I have learned a few basic practices for taking them effectively. Some of those practices include the following:
- Ask purpose-driven questions. Aside from simply discovering the expert’s opinions, every question at an expert’s deposition should serve at least one of these purposes: (1) to support a challenge to the admissibility of the expert’s opinion; (2) to set up your cross-examination at trial; and (3) to establish that the expert’s opinion does not prove an essential element of the opposing party’s claim or defense. Do not simply learn the expert’s qualifications and bases of his or her opinion. Ask each question with a purpose of building an attack on the expert’s testimony.
- Do not conduct your trial cross. You have no audience at the deposition who will decide anything in your case. Also, the jury likely will never hear or see anything from the deposition other than the portions you choose to impeach the expert with at trial. Asking questions that should be reserved for trial at a deposition only previews your trial cross-examination to the witness and opposing counsel, which enables them to prepare for it beforehand. Don’t do this. Rather, be tactical with your questions. Conduct a deposition that sets up your cross-examination at trial, not one that previews it. Also, consider grouping and sequencing questions in a way that obtains the substance you need without revealing the attack you are building.
- Be strategic about using scientific literature. Before confronting an expert with a scientific article or study at a deposition, ask yourself what purpose the confrontation will serve. Will asking the expert questions about it help you challenge the admissibility of his or her opinion? Will something the witness say about it enable you to more effectively attack the witness’s opinion at trial? Or, is the literature effective regardless of what the witness would say about it? Remember, showing literature to a witness at a deposition is not necessarily required in order to use it on cross-examination or to challenge the admissibility of the expert’s opinion. The foundation for its use often can be laid at the deposition in more generic, discrete ways. Also, rarely will an experienced expert witness concede that a study or article is credible evidence against his or her opinions. Confronting an expert with an article or study at a deposition therefore might not provide much benefit. Instead, it might simply reveal a line of questioning you intend to ask at trial and enable the expert and opposing counsel to prepare for it beforehand. So, think critically and strategically about the purpose of using particular scientific literature with an expert witness at a deposition. It might be best to save it for trial.
- Use hypotheticals. Asking hypothetical questions can get an expert to speak more freely about issues to your advantage than he or she would if confronted with questions explicitly incorporating the facts of a case. An expert might not know the facts well enough to recognize that a nuanced hypothetical reflects the particular facts of a case. Or, the expert might not recognize how the hypothetical is being used against him or her. Thus, know the facts of the case well and try presenting them to the expert through hypothetical questions.
- Get clean and direct answers. To effectively impeach an expert with deposition testimony at trial, you need direct and clean answers to your deposition questions. Experienced experts know this. They will skillfully attempt to avoid answering important questions or bury their answers in lines of nonresponsive commentary. Keep coming back to your question until you get a direct and clean answer to it. Don’t stop. Otherwise, you will be left with a useless dialogue a jury will not follow when you attempt to use it for impeachment.
W. Clay Massey is a partner at Alston & Bird, LLP, in Atlanta, Georgia.