Cook County Sheriff FOIA Number One

This is the first request filed as part of our 2018 FOIA Campaign. Our target for this year’s campaign is the Cook County Sheriff’s Office. The Sheriff’s Office staffs and administers Cook County Jail, guards the courts throughout Cook County, runs the Sheriff’s Police. There is far too little information about the daily operations of all three aspects of the office for the public to adequately evaluate the effectiveness of the office. With this campaign CJP is saying this is where the secrecy stops! The office will either open its data or be forced to by the Cook County Courts as a result of our lawsuits based on the failure of the Sheriff’s Office to answer our FOIA requests.

Here is the content of our first FOIA request with the Sheriff’s Office filed on 3/7. Updates will be posted as we recieve responses to our request.


In accordance with the Illinois Freedom of Information Act, 5 ILCS 140, provide in machine-readable digital format the following records:

1.  All individual-level data or datasets recording, regarding, or reflecting admissions to and releases from Cook County Jail from January 1, 2000 through December 31, 2017.

2.  Any database of individual admissions to and releases from Cook County Jail from January 1, 2000 through December 31, 2017.

3.  Any available data or dataset, including archival data, tracking or recording the admissions of individuals to Cook County Jail and releases of those same individuals from Cook County Jail from January 1, 2000 through December 31, 2017.

4.  The complete database(s) used by Cook County Sheriff’s Department employees to track the admission and release of individuals from the Cook County Jail.

5.  The data dictionary relevant to any of the data sets in 1-4 above.

6.  Training or instructional materials relevant to any of the data sets in 1-4 above.

“Machine-readable digital format” means, if possible, an excel file or a comma delimited file

“Releases” means any discharge, release, transfer or any event which resulted in an individual in the custody of the Cook County Jail being no longer in the custody of the Cook County Jail.

“Individual-level” means on a person-by-person basis, not data aggregated over multiple individuals.

“Individual admissions to and releases from” means the admission of a particular individual person and the release of that same individual person.

“Data regarding or reflecting admissions and releases to/from Cook County Jail” means any available data about such admissions and releases, including but not limited to: identifying information for such individual, admission date, release date, facility and unit admitted to, location, admitting officer, alleged offense, reason for release

“Database” means any collection of information that is organized so that it can be electronically accessed, managed and/or updated.

“Data dictionary” means any set of information describing the contents, format, and structure of a database and the relationship between its elements, used to control access to and manipulation of the database.

“Training or instructional materials” means materials used by the agency to train or instruct users on how to use, access, enter data into, retrieve data from, and/or maintain the data in the databases or data sets.

If the agency plans to withhold any field in this data for any reason, for every such field withheld, provide a detailed explanation of the contents of each such withheld field and cite the exemption you are invoking to withhold such field.

Please fulfill this request in the 5 working days allotted by Illinois law. Please direct all questions or responses to this FOIA request to this email address by responding to this email.

Tracy has nearly two decades of experience researching and working within criminal justice systems. When Tracy began pursuing a career dedicate to system reform, he found that no single organization existed to promote evidence-based discussions among law enforcement agencies and the communities they serve. Recognizing that citizens in Chicago deserved the right to demand transparency in their criminal justice system, Siska established the Chicago Justice Project. He received his Master of Arts degree in Criminal Justice at the University of Illinois at Chicago.

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