New CSV of Reporters of Decisions

One of the projects we maintain at Free Law Project is a database of reporters of judicial decisions. This database has been popular among developers, but we’ve heard that the data was hard to work with.

To fix this, we created a new CSV of the data that is available now. It currently has 440 reporters.

For each reporter, we collect the following information:

  • Any series that the reporter has, for example, a 2d or 3d.
  • Any variations that the abbreviation for the reporter may have. For example, Kentucky Reports can be cited variously as, “B. Mon.”, “Ky.(B.Mon.)”, “Mon.”, “Mon.B.”, or “Monroe, B.” We have nearly 1,000 of these so far.
  • The start and end dates for each series of each reporter.
  • The jurisdictions covered by each reporter.

Together, this information is vital for creating citators and for identifying what decision a citation actually refers to.

More information about the database can be found on its page here. We have used this database in production on CourtListener for years and we believe the collection of reporters is nearly complete. However, we do need help getting the start and end dates for each reporter series. If …

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Ending our PACER Drainage Initiative and Stopping our Email Lists

We at Free Law Project have been working towards our goals for a few years now, and as a result we’ve accumulated a bit of cruft. Today, we shed just a bit of it, as we simultaneously end one of our smaller projects and deprecate our list server.

The project we are ending is our PACER Drainage project. The idea of the project was to put pressure on PACER by having lots of people use their $15 fee waiver to download PACER content to the RECAP archive.

The main reason we’re ending this project is because PACER is vast, and we never got the kind of uptake we needed for this program to be successful. We knew that we’d never make a big impact on PACER unless thousands of people started using their fee waivers to download content, but we went ahead with this project anyway for two reasons. First, we wanted to be part of the effort last year to apply pressure to PACER, and second, we wanted to raise awareness about the PACER issue via a direct call to action.

While I don’t think we succeeded in applying the pressure we wanted (the AO …

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More Information about our Judicial Database and Some Responses to Feedback

Robert Ambrogi recently wrote an article about our new judicial database for his LawSites blog. In his article, he makes a few concrete observations about our judicial database, and I want to use these observations as a launching point to talk some more about what we have made, why it is useful, and what we are working on next.

The two observations Robert makes are:

  1. Our page for Justice Robert Cordy is sparse compared to the same page on Ballotpedia.

  2. Scalia’s end date was not set for his time on the Supreme Court, and his education data was not quite correct.

These kinds of observations are really important to us, and it shows that we still have work to do building and explaining our work.

On Sparseness

To the first observation about Robert Cordy, our response is that we’re building a database, not a more free-form wiki. Unlike the incredible work Ballotpedia is doing, which allows almost any kind of information, our work is focused on gathering specific facts about judges and appointing officials. This approach has pros and cons, and Robert is fair to point out that our data about this important judge is fairly sparse. He …

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Notes and Sketches from Making SCOTUS Network Visualizations

A design sketch with case names

A sketch showing links between cases (click for enlarged view)

In February we announced our Supreme Court Citation Network tool that we developed with University of Baltimore School of Law. We haven’t had a chance until now to comment on some of the technical difficulties that came up while we were working on it. If you’re not familiar with this tool, you should take a moment now to go check it out (gallery, homepage).

In this post I’ll be talking about the challenges that we overcame in order to efficiently generate these visualizations. If you like what you read here, you might want to vote (hint, hint) for Colin Starger’s talk at the Cali Conference.

In the Beginning…

A goal at the start was to create a system that could quickly generate these diagrams in response to a user’s request, without resorting to any kind of “please wait” mechanism such as a spinner () or any other tricks that might frustrate our users. This would turn out to be a very difficult goal beacuse of the nature of citation networks.

In a database like ours, the data is organized into tables, much like in an Excel …

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CourtListener Podcasts Now on Google Play

Google Play Logo

Just a quick post today to share that our oral argument podcasts are now available on Google Play Music.

If you are a user of Google Play Music, you can easily subscribe to our podcasts by searching for “Free Law Project”, “CourtListener”, or simply, “oral arguments”. Once you subscribe, the podcasts will download to your device if you use one, or will be playable via the website.

These podcasts contain all of the oral argument audio for a given court or for a search that you create. This means that in 2016, you can literally pipe the audio from the Supreme Court and Federal Circuit Courts directly to your pocket.

In honor of this announcement we’ve created a new page on our site that lists our existing, pre-made podcasts, explains how to make custom ones, and explains how to subscribe to them in Google Play Music or Stitcher Radio.

We hope you’ll enjoy these podcasts. Who doesn’t want the Supreme Court piped to their pocket?

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Free Law Project and Princeton/Columbia Researchers Launch First-of-its-Kind Judicial Database

A screenshot of President, Judge Taft

President Taft’s Biography Page

Today we’re extremely proud and excited to be launching a comprehensive database of judges and the judiciary, to be linked to Courtlistener’s corpus of legal opinions authored by those judges. We hope that this database, its APIs, and its bulk data will become a valuable tool for attorneys and researchers across the country. This new database has been developed with support from the National Science Foundation and the John S. and James L. Knight Foundation, in conjunction with Elliott Ash of Princeton University and Bentley MacLeod of Columbia University.

At launch, the database has nearly 8,500 judges from federal and state courts, all of which are available via our APIs, in bulk data, and via a new judicial search interface that we’ve created.

The database is aimed to be comprehensive, including as many facts about as many judges as possible. At the outset, we are collecting the following kinds of information about the judges:

  • Biographical information including their full name, race, gender, birth and death dates and locations, and any aliases or nicknames that a judge may have.

  • Their educational information including which schools they went to, when they went, and …

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It’s easier than ever to contribute to CourtListener and Free Law Project

Working on complex software with a lot of dependencies can be difficult, and over the years many people have struggled to install and configure all the complex components CourtListener requires. Our previous solution to this was to create and maintain the Free Law Virtual Machine, which allowed people to work in a VM with all the right software installed. Alas, keeping the VM maintained was a real burden and we weren’t the best at it. It fell into decay and without realizing it we informally stopped recommending people use it.

Today we have a new, more modern solution using Vagrant. We’re getting the last of the kinks out of the new system, but already a number of people are using it in their daily process. It has all of the dependencies installed and configured. Best of all, although your code will be running in a virtual machine like before, when you’re using this setup, you still get to use all of your favorite tools on your local machine. If you haven’t used Vagrant before, you’ll find it’s a rather magical experience.

If you’re a contributor to CourtListener it’s definitely worth checking this …

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Our Newest Launch: A SCOTUS Data Viz Tool

We here at Free Law Project are happy to announce the launch of our Supreme Court Citation Network tool. Created in collaboration with the SCOTUS Mapping Project at the University of Baltimore, the tool permits users to create citation networks that represent “lines of cases” in Supreme Court doctrine. With the tool, users can also visualize, analyze, and share the networks they create.

Consider the network above. It was created with the tool and embedded directly into this post. Similar to a YouTube video, you can interact with it, hovering on the nodes to see the full case name, or clicking them to open them in a new tab. Of course, you can also open the visualization in its own page, where you’ll find more detail and analysis.

The visualization leverages Supreme Court Database (Spaeth) to show a surprising fact about the recently departed Justice Scalia: He was a liberal on the Fourth Amendment. The map is anchored by two Scalia opinions in which the supposedly conservative justice sided with an accused marijuana criminal — Kyllo (protecting weed grower from warrantless thermal imaging search) and Jardines (protecting weed grower from warrantless dog sniffing search).

After you’ve created a visualization …

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Some Citation Parsing Statistics

We want to share some quick statistics today. We we just completed running our citation parser across the entire CourtListener collection. If you follow our work, you’ll know that the purpose of the citation parser is to go through every opinion in CourtListener and identify every citation from one opinion to another (such as “410 U.S. 113“). Once identified, the parser looks up the citation and attempts to make a hyperlink between the opinions so that if you see a citation while reading, you can click it to go to the correct place.

As you can imagine, looking up every citation in every opinion in CourtListener can take some time, so we only run our citation finder when we need to. In this case:

  • The process ran continuously for two weeks.
  • It ran a total of 253,872,460 queries against our search engine.
  • It found 25,471,410 citations between opinions.
  • There are about three million opinions currently in CourtListener.

After running the parser, the first stop I like to take is to go and see the search results ordered by citation count. In an upset, Strickland v. Washington, the former leader, has been pushed to third …

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Releasing V3 of the API, Deprecating V1 and V2

This post is one with mixed news, so I’ll start with the good news, which is that version 3.0 of the CourtListener API is now available. It’s a huge improvement over versions 1 and 2:

  • It is now browsable. Go check it out. You can click around the API and peruse the data without doing any programming. At the top of every page there is a button that says Options. Click that button to see all the filtering and complexity that lies behind an API endpoint.
  • It can be sampled without authentication. Previously, if you wanted to use the API, you had to log in. No more. In the new version, you can sample the API and click around. If you want to use it programatically, you’ll still need to authenticate.
  • It conforms with the new CourtListener database. More on this in a moment, but the important part is that version 3 of the API supports Dockets, Opinion Clusters and Sub-Opinions, linking them neatly to Judges.
  • The search API supports Citation Searching. Our new Citation Search is a powerful feature that’s now available in the API.
  • Bulk data now has metadata. In response to a …
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Citation Searching on CourtListener

One of the great new features that the new version of CourtListener provides is what we’re calling Citation Searching. Citation Searching lets you look at all the opinions that cite an opinion you’re interested in and then slice and dice them so that you only see the ones that are important to you.

For example, say you’re looking at Roe v. Wade and you want to analyze the cases that have cited it. In CourtListener, in the sidebar on the left, there’s a list of the opinions citing the one you’re looking at, in the section called “Cited By”. At the bottom of that section, there’s a link that says, “Full List of Cited Opinions”.


If you click that link, you’ll be taken back to the search results page, and you’ll see that your query is for cites:(108713). The number in there is the ID of Roe v. Wade that you can see in its URL. This is just standard CourtListener search syntax, so you can tweak it however you like.

For example, another important case in this area is Planned Parenthood v. Casey, which has an ID of 112786. If …

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Millions of New “Short Form” Case Names Now on CourtListener

While working on a soon-to-be-released feature of CourtListener, we needed to create “short form” case names for all the cases that we could. We’re happy to share that we’ve created about 1.8M short form case names, including complete coverage for all Supreme Court cases going back to 1947, when the Supreme Court Database begins.

If you’re not familiar with the term, short form case names are the ones you might use in a later citation to an authority you’ve already discussed in a document. For example, the first time you mention a case you might say:

Kellogg Brown & Root Services, Inc. v. United States Ex Rel. Carter

But later references might just be:

Kellogg Brown at 22

The Blue Book doesn’t have a lot to say about this format, but does say the short form must make it, “clear to the reader…what is being referenced.” Also:

When using only one party name in a short form citation, use the name of the first party, unless that party is a geographical or governmental unit or other common litigant.

With these rules in mind, we made an algorithm that attempts to generate good short form …

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Many Improvements Released in New CourtListener Version

It’s taken the better part of a year, but I’m thrilled to announce that a new and better version of CourtListener is live as of this moment. If you can’t tell the difference immediately, we see that as a good thing, since most of the enhancements are under the hood.

  • The most important changes in this version have to do with the database, which now supports a number of new features. Most importantly, legal opinions are no longer single entities. For example, in the past if we had the lead opinion, a dissent, and a concurrence, we had no choice but to put them all together and make them readable top to bottom on our site. That has been fine, but in our new system we introduce the concept of an Opinion Cluster, which consists of several “sub opinions”.

    This will let us have links from a dissent to a concurrence, something we couldn’t do before. Or we can change the way the “sub-opinions” are displayed so that you can easily go straight to the dissent or the concurrence, without having to scroll endlessly. In a similar way, we are now introducing dockets, which will soon …

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Launching Website

A quick announcement today to share that we’re making our new home and that we’re launching a new homepage to go with it. If you’re reading this post, you’re looking at the new site! Let us know what you think or if we can improve it somehow. For the most part, it’s a replica of our old site, but we’ve made a few improvements here and there. In general, the layout, typography, security, speed, and reliability should all be better.

In addition to the new homepage being live, we also updated our email, so you can now reach us at

We love preserving digital artifacts, so here’s a screenshot of the old site:

Old Homepage, v1. You can also browse the old site at

For the technically curious, this new site uses the Pelican Static Site Generator, and runs on the Amazon Web Services stack. This means that it will be incredibly fast no matter where you are in the world, it should never go down, and it allows us to secure the page behind HTTPS. If you want more details, you can find them in …

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Our New Citation Finder

CourtListener now has a new citation finder that you can use with any citation in our system. It’s dead simple. There are two ways to use it.

Either simply type in the citation you want to look up:

Citation Lookup

Or, just make a link with a format like:


And you’ll get to the page for that citation. For example, using parallel citations, any of these links will take you to Citizen’s United v. Federal Elections Commission:

This new tool relies on our existing citation extractor, which extracts thousands of citations from opinions every day. As a result, these links are also able to handle alternate names for any reporter that we have encoded in our Reporters Database. For example, the United States Reports has historically also been abbreviated as “U.S.S.C.Rep.” or “USSCR”. Use either of these, and you’ll find that they also work without a hitch:

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The Right to Read Anonymously

In 1996, in the Connecticut Law Review, legal scholar Julie Cohen wrote what has become a landmark article in Internet Law entitled, “A Right to Read Anonymously: A Closer Look at “Copyright Management” In Cyberspace.” She began by stating,

A fundamental assumption underlying our discourse about the activities of reading, thinking, and speech is that individuals in our society are guaranteed the freedom to form their thoughts and opinions in privacy, free from intrusive oversight by governmental or private entities.

Cohen notes that, in the past, our right to read anonymously has been protected by libraries and librarians. See, for example, the American Library Association’s Freedom to Read statement, adopted in 1953. Our American experience has generally been that one is able to walk into a public library, take almost any book off the shelf, sit down, and read without ever identifying oneself or asking anyone’s permission. Most libraries, as vigorous defenders of reader privacy, only maintain information about which books you check out until you return them and then they destroy any record connecting your identity to the books checked out. It was, in 1996, the growing prevalence of electronic dissemination of information and technologies to monitor …

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New Juriscraper Email List

Update: We’ve moved our development conversation over to Slack. If you wish to join us there, please get in touch using our contact form.

Quick post today to share that by popular demand, we’ve created YAEL — Yet Another Email List. Today’s list is one we should have made a while back, and is for folks that work on the Juriscraper library. You can find and add yourself to the list here:

In general, this will be a normal list where we’ll post any important updates about Juriscraper, but this list will also get one special email per day documenting the status of our 200+ court scrapers. Previously this email was only sent privately to maintainers, but by making it public, we’re hoping to encourage more people to identify and fix the day to day problems that arise with so many scrapers.

Scraper Status Email

Yesterday’s status email

We look forward to lots more discussion and so much more scraping!

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Free Law Project and University of Baltimore to Collaborate to Create Supreme Court Doctrinal Maps

An early prototype of the new version.

An early prototype of the new version.

Free Law Project is excited to announce that over the next several months we will be collaborating with the University of Baltimore and Assistant Professor of Law, Colin Starger, to build a web-based version of his Supreme Court Mapping Project, a software-driven effort to visualize Supreme Court doctrine. Currently a desktop software tool, the collaboration will move this functionality to the web, incorporating it directly into Free Law Project’s CourtListener platform.

Once incorporated into CourtListener, users will be able to create visualizations of how different cases cite each other, including plotting them against variables from the Supreme Court Database such as whether the case had a liberal or conservative outcome, and the minority/majority votes of the justices. Using the CourtListener citation API, Colin and his partner Darren Kumasawa have done a lot of work in this area already, laying a great foundation for this project.

The current design The current design

We hope that within a few months our new service will go live, and that teachers, librarians, and researchers will be able to create great new visualizations of Supreme Court doctrine. If you’ve been watching Colin and Darren’s work over on …

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AI and Law Call for Papers

Passing along this call for papers:

Special Issue of Artificial Intelligence and Law in Honor of Carole Hafner: call for papers

Earlier this year, Carole Hafner, a key figure in the origin and development of AI and Law, died. A tribute to Carole can be found at A special issue of Artificial Intelligence and Law (which she co-founded) will be published in 2016, focusing on Carole’s main research topics: semantic retrieval and the procedural, temporal and teleological aspects of reasoning with legal cases.

In her long academic career, Carole Hafner made contributions in a number of areas of AI and Law. Her 1978 Ph.D. dissertation was a pioneering effort in semantic information retrieval of legal cases; ahead of its time, it supplied what would now be called ontologies for describing case law domains and cases, a retrieval language, and methods for retrieving, from a corpus of a hundred cases, cases providing: examples of which a specified concept is (or is not) true, criteria for knowing that the concept does (or does not) hold, or the consequences of the presence or absence of the concept in a particular case. Today, developments in …

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