In personal injury trials a major focus is often the legitimacy of the plaintiff's alleged injuries. If the defendant doubts the severity of the plaintiff's injuries, it is common practice for the defendant to hire private investigators to conduct surveillance of the plaintiff. The knowledge, prior to trial, of the existence and contents of any surveillance is imperative for plaintiffs, either to substantiate the extent of injuries alleged,4 or to prepare an argument to explain any discrepancies between the injuries alleged and those shown by the surveillance A defendant's interest in the non-discoverability of surveillance stems from a desire to keep the plaintiff honest when she testifies about the extent of her injuries, Currently in Missouri, surveillance materials are protected as work product, and this protection has not been overcome by a showing of substantial need and undue hardship.
Kenneth E. Siemens,
Discoverability of Personal Injury Surveillance and Missouri's Work Product Doctrine, The,
57 Mo. L. Rev.
Available at: https://scholarship.law.missouri.edu/mlr/vol57/iss3/4