The Free Law Ferret plugin for Firefox is a legal research companion to the Multilingual Zotero (aka MLZ) reference manager.
The Ferret reads US case law citations from any page viewed in the Firefox browser. Citations can be saved directly to MLZ; the corresponding court judgements are opened automatically in separate browser tabs, and can be appended to their MLZ items with a couple of clicks apiece. Items can be tagged locally for quick targeted retrieval, annotated for future reference, and accurately cited into new documents with a single click.
The Ferret is the first tool of its kind: if you work with US legal materials, it may save you valuable time in the collection of cited cases and the organisation of arguments.
Setup and Usage
Once you have Firefox in place, install the Multilingual Zotero and Free Law Ferret plugins, in that order. Clicking on the logos to the right should do the trick.
Firefox will ask for permission to proceed with the installation and offer to restart the browser for each plugin. Just say “yes”: no further configuration is required to set things up. Once both plugins have been successfully installed you’re ready to go.
The Ferret reads citations from ordinary web pages (not PDF files, at least as of this writing). The sample to the right is from CourtListener, but the text of judgements obtained from Google Scholar, Justia, Lexis or WestLaw will suit just as well. The Ferret will process pages from online legal guides, and presumably The Bluebook Online itself (I am unable to confirm the last item, as the editors have warned me off opening an account there, for reasons that they have yet to fully explain).
Before using the Ferret, wake up the MLZ library by opening it at least once. You can either use the Shift-Ctrl-Z hotkey combination (Shift-Cmd-Z on a Mac), or click on the MLZ icon in the lower-right corner of your browser. Repeating the operation will close the library view. (The illustration to the right shows a sliver of my own library: when MLZ is run for the first time, it will contain only the Zotero Quick Start Guide.)
Right-click the mouse to open the context menu. A “Free Law Ferret” menu option should appear at the bottom (highlighted in the illustration to the right). Click on the menu option to run the Ferret across the page.
After scanning the page, the Ferret will display a list of citations it has found, as shown to the right. Select the cases that you would like to open for viewing. To create MLZ items when cases are opened, tick the “Save selected items to MLZ” option above the “OK” button (this is generally desirable, so tick the box now).
A search for each selected case will be opened in a fresh browser tab. The illustration to the right shows a search of the CourtListener database. This is the Ferret’s preferred source for cases: if no results are found there, the will fall back to Google Scholar. In both services, the citation of the case being searched for is displayed at the top of the page (item  in the illustration). If the CourtListener search is overbroad (unlikely, but possible), you can adjust the search terms by editing the case name words used (item  or the jurisdiction searched for (item ). In the illustration there is only one search hit and the citation matches, so we can just click through to obtain the text of the case.
When the case itself is opened in its browser tab, the Ferret will check whether a record of the case exists in the MLZ database (if the “Save selected items to MLZ” option was ticked, this will always be true). If a record is found, a green icon will appear in the address bar as shown in the illustration to the right. Clicking on the icon will automatically attach the text of the case to the local MLZ item. The icon will then disappear.
Once the case text has been saved with the green icon, repeating the steps above will open the local copy, rather than performing a search on CourtListener (or Google Scholar). Local copies can be opened without access to the Internet.
That’s pretty much the Ferret in a nutshell. MLZ has powerful facilities for organising, sharing and citing materials (which it inherits from the parent project at Zotero proper) and these are well worth exploring. Guidance on the use of Zotero is available from the Zotero website. For information on the extended features of MLZ, please refer to the book Citations, Out of the Box, available in print form on Amazon, or as a downloadable PDF. Before you dive down the rabbit ferret-hole, there are a couple of points to note:
- A set of MLZ styles with legal citation support are available here on the CitationStylist website. You should use these for legal writing, rather than styles from the official CSL style repository. The selection is much smaller, but the MLZ styles are able to do a better job of formatting legal references.
- When seeking support on the Zotero forums, be sure to put [mlz] in the subject line of your post, so that volunteers and core developers who follow forum traffic will know that your question relates to MLZ rather than the official version of Zotero.
I hope you enjoy the Ferret. I’m rather fond of the little critter myself; it’s nearly housebroken, and I’m looking forward to seeing what tricks it will be put up to by those who take it out for a walk.