Texas has a rule that permits presuit depositions to be taken, not just be preserve testimony but also to do discovery to determine the merits of a claim before filing suit.
Professor Lonny Hoffman has written about the subject. Here is an abstract of the article:
"What is the relationship between access to information and access to justice? Private parties obviously have many publicly available points of access to the information they seek in order to file a lawsuit. Lawyers can talk to their clients and other willing witnesses. Documents can be gathered. Specific statutes may sometimes permit information to be obtained before a formal lawsuit is brought. On other occasions, however, information needed or desired will lie solely within the exclusive knowledge and control of another. The ability of private parties to compel the production of information, documents or testimony before litigation rarely has been seriously considered as a factor bearing on access to court. Beyond the lack of treatment of the doctrinal sources of authority, no attempt has been made by academic commentators or those most closely involved in civil procedural reform to gather empirical evidence to try to fix how important to the institution and maintenance of civil suits is the right to take presuit investigatory discovery. This Article seeks to fill these vital gaps that exist in the literature and in the public debates, more generally, over access to justice. After examining the available authority in the federal and state courts, the author gathers and reports on original empirical research conducted on the use of presuit investigatory discovery by private parties. That data comes from Texas, where the state rule provides the broadest grant of authority to prospective litigants to invoke judicial process for investigatory purposes. The empirical evidence from Texas may reasonably be read as indicating widespread use of the state’s presuit discovery rule, most likely on the order of approximately one out of two lawyer and judge respondents reporting at least one experience in which a presuit deposition was taken. Relatedly, it appears that approximately 60% of the time the deposition was taken to investigate a potential claim before suit was filed; the remaining 40% of depositions were secured for the purpose of perpetuating testimony. Examining the available data, the author argues that there are good reasons to believe that the perceived need to satisfy formal legal requirements to bringing suit, as well as the pull of practical considerations, may plausibly explain the incidence of use of the state’s presuit discovery rule. Read in this manner, the empirical evidence suggests an important relationship exists between access to information and access to justice."
