Among the many significant contributions made to the federal judiciary by the late Judge Donald Voorhees is the Manual on Recurring Problems in Criminal Trials. During his tenure on the Federal Judicial Center's Board from 1979 to 1983, Judge Voorhees developed the manual to assist his fellow judges in researching important issues that arise frequently in criminal trials. Many federal judges have found the book to be an invaluable resource-a research tool that enables them to quickly locate authority on specific issues that often confront them. Although in this edition, as in the previous one, the editors have added some material and made some changes in organization and format, the manual adheres to Judge Voorhees's original concept of simplicity and ease of use. As his "Caveat" (written to accompany the third edition) emphasizes, the book is not meant to be a comprehensive treatise on criminal law, but rather a basic guide to the law governing many of the procedural matters that arise frequently in criminal trials. Consequently, the manual should not be cited as authority in opinions or other materials, nor should the case summaries, which have been updated through October 2000, be considered substitutes for the judicial opinions they reference. We at the Center take pride in continuing the work begun by Judge Voorhees with the publication of the fifth edition of his manual.