Study of a wide array of the evidential and inferential issues encountered in our system of law occupies researchers from many different disciplines. Much attention has focused on the behavior of jurors, attorneys, and judges. Of equal importance, though not so frequently studied, are the various inferential and decisional tasks required of others such as investigators and advocates. The manner in which investigators and advocates play their roles has a direct bearing upon subsequent inferences and choices made by other actors in the legal system. This research concerns the inferential and decisional roles played by investigators and advocates during fact investigation and other activities before a matter comes to trial or is settled by other means. The objectives of the project are to study ways of marshalling or organizing evidence that will enhance reasoning, structuring complex arguments, and assisting in decisionmaking at various points during the preparation of criminal or civil cases. The study involves computer-assisted simulations of complex cases that will result in the structuring of "inferential networks" of evidence marshalling methods. This research is not only of theoretical and practical significance in a legal context, but also bears on inferential and decisional behavior in many other important contexts such as medicine, science, business, and intelligence analysis. The results promise to introduce new levels of rigor, clarity, and fairness into the technology of proof and persuasion. The linked networks of prototype computer-based evidence marshalling systems will be useful in illustrating theoretical issues in the practice and teaching of fact investigation and may provide the sound inferential basis now lacking in many current efforts to develop computer-based litigation and other inference-related systems.