This NIJ Special Report presents results of a study that used dd—a disk imaging tool—in the UNIX-based FreeBSD 4.4 environment. It documents results against 22 test assertions (both mandatory and optional), describes the testing environment, interprets results, and includes summary log files of 32 test cases. The results provide information necessary for developers to improve tools, users to make informed choices, and the legal community and others to understand the tools' capabilities.