JTT - a JailTracker tracker

JTT is a collaboration with another project: @bfeldman89's jail_scrapers, which focuses on gathering data about Mississippi jails. Please see https://bfeldman89.com/projects/jails/ for information about this work.

As JailTracker is utilized in many places outside of Mississippi, this code has been separated from jail_scrapers for those interested in similar civic hacking projects.

About JTT

JTT uses the API of the JailTracker software suite in order to aggregate information about inmates for civic purposes. We're interested in answering questions about treatment of inmates, including but not limited to:

How long are inmates held pre-trial? Pre-arraignment?
How long are inmates being held without being charged at all, or when charges are dropped before trial?
Does this data vary along demographic or geographic lines?

JTT is not for your mugshot website, and support for downloading mugshots will not be added.

Usage

See example.py for a complete example of how to use JTT to get a JSON data set of however many jails you're interested in.

JailTracker URLs

When you visit a JailTracker page, have a look at the address bar in your browser. The URL will look something like "https://omsweb.public-safety-cloud.com/jtclientweb/(S(3r01ougmulvelofaoxij53r4))/jailtracker/index/HANCOCK_COUNTY_MS". The (S(3r01ougmulvelofaoxij53r4)) is JailTracker's funky way of handling session keys. If you try to reuse the above link, you'll probably get a new session key.

However, to get a key without having one in the first place, you could have just gone to https://omsweb.public-safety-cloud.com/jtclientweb/jailtracker/index/HANCOCK_COUNTY_MS. Note - this just omits the key component altogether! JailTracker will respond to your request with 302 Found, and you'll be redirected to the address specified in the Location header of the response. This address contains your new session key.

Fortunately, JTT handles that part for you. The simplest use case looks like this:

import json

hancock = jailtracker.Jail('https://omsweb.public-safety-cloud.com/jtclientweb/jailtracker/index/HANCOCK_COUNTY_MS')
data, err = hancock.process_inmates()
if err is not None:
    print(err)
else:
    print(json.dumps(data, ensure_ascii=False, indent=4))

Finding your jail's URL

Often, a sheriff's department will embed the JailTracker page in their website. For example, see http://www.hancockso.com/InmateRoster/hancock_inmatelist.html. (Sorry, no TLS.)

Here's how to get the URL described in the previous section.

Using the Firefox browser:

Right click inside the JailTracker frame
Choose "This Frame", then "Show Only This Frame"
You'll be redirected to the omsweb page. Copy the URL from your address bar.
Finally, reference the previous section to learn how to remove the unneeded session key from the URL.

Chrome doesn't provide the same feature. Instead, you can:

Right click inside the JailTracker frame
Choose "Show frame source"
The source code for the JailTracker page will open in a new tab. The address bar of this new tab should contain the URL you want. Just strip off the view-source: bit at the beginning.
Finally, reference the previous section to learn how to remove the unneeded session key from the URL.

Data modeling

To our knowledge, JailTracker doesn't publish its internal data model.

In general, jails do tend to publish the following:

A summary for each inmate (returned as a list for GetInmates)
A detailed inmate report for a given arrest number (GetInmate)
A list of cases for a given arrest number (GetCases)
A list of charges for a given arrest number (GetCharges)
- For some reason, this is done via a POST request, not a GET. Go figure.

Note: some jails are rather inconsistent with what they provide. For example, only a small percentage of inmates (or none at all) might have case or charge data available.

Relational data stores

It's easy to use JTT to produce a JSON file of all the data you pull. See the included example.py.

However, if you want to use a relational data store, you need to know what tables and columns belong in your data model. To help with this, the script getcolumns.py is included. It reads jail data from a file called results.json - which you can produce using example.py, and it produces two files - column_totals.json and column_results.json.

You can use the two resulting data sets to figure out the following:

What columns are needed for each data type (table)?
- column_totals.json is the easy way to read this
For a column of interest, which jails provide that information?
- See column_results.json

Known issues with available data

Some jails (e.g. Harrison County, MS) require that you provide at least two characters in the "Last Name" field, otherwise no data will be provided.

As previously mentioned, some jails don't consistently provide case or charge data.

bfeldman89/jtt