When discovery is provided in the form of scientific reports, it is insufficient for adequate trial preparation. In addition, some courts still refuse to recognize an accused's right to test evidence independently. There is little dispute that pretrial discovery is necessary when using scientific and expert evidence. The most basic discovery need concerning scientific evidence is advance knowledge that an expert will testify at trial. Mere notice that an expert will testify, however, is not adequate. The opposing party needs to know both the substance of the expected testimony and the qualifications of the proposed expert. The expert's report should identify all analysis techniques and personnel involved in testing. DNA evidence involves statistical proof and other complex issues, and the need for extensive discovery is self-evident. Discovery should include the right to test and retest DNA evidence previously analyzed by prosecution experts, although the right to retest may involve significant expense. The right to test necessarily implicates a duty on the part of the State to preserve evidence. It is recommended that current discovery rules be amended to provide notice that an expert will testify, the substance and basis of expected testimony, and the right to test and retest evidence. 205 footnotes