I stumbled across what could be a promising archival project involving the California appellate courts:
In 2006, the California Appellate Court Legacy Project was undertaken to interview all retired justices in the state, as well as active justices who may be nearing retirement. Overseen by the Appellate Court Legacy Project Committee (chaired by Associate Justice Judith L. Haller of the Fourth Appellate District, Division One), interviews are videotaped or audiotaped and conducted by interviewers selected from within the appellate branch. Ultimately the tapes will be made available to judicial colleagues, historians, scholars, law students, and members of the public. The resulting archive will be an historical record of both the personal experiences of individual justices and the evolution of the
California appellate courts.
Unfortunately, I haven't found any information about the project's current status or what types of questions the interviewers are asking the judges. Actually, I can't find much of anything about this project other than the statement above, which comes from the California Courts' website.