Evidence is both "[s]omething (including testimony, documents and tangible objects) that tends to prove or disprove the existence of an alleged fact" and "[t]he body of law regulating the admissibility of what is offered as proof into the record of a legal proceeding." Evidence, Black's Law Dictionary (11th ed. 2019).
A sampling of the materials Jenkins has on evidence is listed in this guide. For more sources, try searching the Jenkins' catalog for evidence. The search results can be limited by adding additional terms to the search or by modifying the search to a specific library location, i.e. General Collection, Pennsylvania Collection, or State Collection. For help, members can contact Research Services at 215.574.1505 or firstname.lastname@example.org.
For resources on electronic evidence, see the Electronic Evidence & Discovery guide.
Court rules often outline how evidence can be discovered and admitted in court as well as how discovery and interrogatories can be conducted. See the Pennsylvania Court Rules - County, Pennsylvania Court Rules - State, and Federal Court Rules guides for where to find court rules. Jenkins also has court rules for all 50 states and the District of Columbia. A search of the Jenkins' catalog for court rules and the jurisdiction should find the relevant materials.
Materials focused on discovery may also cover evidence. See the Discovery Practice guide for additional resources.