Extracting Confidential Information from Public Documents: The 2000 Department of Justice Report on the Federal Use of the Death Penalty in the United States

Research is growing on methods to balance two competing public purposes: the need of the public for information about society and government, and the right to privacy and confidentiality of individual information. This article presents a case study in which a governmental agency (the U.S. Department of Justice) released a report (on federal capital cases, 1995--2000) seeking to conceal certain information (the recommendations of the U.S. Attorney and the DOJ Review Committee on whether to seek the death penalty), while releasing cross-tabulations of the concealed information with other, public information about the cases. Careful study of the released cross-tabulations led to full identification of all the variables in 386 out of 682 cases. Using other public data led to full identification of another 160. For the remaining 136 cases, the space of possible values for the missing data is drastically reduced. This article explains how the inferences were made.