Building a Free, Open Source Legal Citator

The law is public domain, but there is a lack of free and open access to the law. Legal research today is dominated by two commercial organizations, Westlaw and LexisNexis. As a result, the best tools are not accessible outside of law schools and large firms except at a high price. While free legal resources such as Justia and Google Scholar exist, none of them provides a citator – a tool for researchers to trace the history of issues and cases via citations between opinions.

For our project we built a functioning legal citator into CourtListener, an open-source legal database created and maintained by I School alumnus Michael Lissner. This online application detects citations in court opinions, creates links between cases, and tracks the resulting citation network. We also created an exploratory information visualization of the relationships between cases.