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Information Technology Standards: What Chiefs Need to Know about XML

By Paul Embley, Chairman, Global XML Standardization Task Force

Every day, law enforcement executives deal with such critical issues as budgets, media inquiries, and officer safety. It is unlikely that technologies like eXtensible Markup Language (XML) are anywhere on that list. Because XML may not directly help police chiefs when they go before the city council or when they meet with reporters, some chiefs may be tempted to leave XML and other technology issues to the technology staff.

But information technology is worth the law enforcement executive's attention. It is increasingly woven into all functions of policing: getting critical information to the officer on the street could save his or her life; having the right intelligence available to an investigator could prevent a catastrophic event; receiving timely information from the crime lab could secure a conviction of a dangerous felon; and reducing the redundancy of data collection and reporting could save money. As the desire for information technology in the justice community grows, so does the need for leadership in technology issues.1

The Global Justice Information Sharing Initiative, known as Global, is working to help police executives and other criminal justice practitioners use XML and other information technologies. One of the group's projects, the Global Justice XML Data Model (GJXDM) sets standards for criminal justice information technology. Global just released version 3.0. The model includes the Global Justice XML Data Dictionary (GJXDD), which defines the roughly 2,000 terms criminal justice agencies rely on when they share information.

This article is designed to tell law enforcement executives what they need to know about the standards and the dictionary, what it will mean to conform to those standards, and what is planned for the future.

The Standards: GJXDM
XML, a standard issued in 1998, has been identified by the justice community as a promising technology to securely and efficiently share information among disparate systems. The standard enables structured data, like that found in law enforcement records management systems (RMS), to be represented in a way that it can be transported and translated to other systems smoothly. The GJXDM began as the Global Justice XML Data Dictionary (GJXDD), an effort to reconcile XML data definitions used by the justice community. The goal was to develop common definitions among law enforcement, prosecutors, courts, corrections, and other private and public justice organizations to facilitate electronic information exchange in the justice community. The Global Justice Information Sharing Advisory Committee (GAC) championed the project, sponsored by the U.S. Department of Justice's Office of Justice Programs. It soon grew into an effort to develop a general framework organized around objects and relationships.

Version 3.0 Released: An operational version (3.0) of the GJXDM has been officially released and is available at ( As with any software development, work on the next version of the GJXDM began almost as soon as 3.0 had been released. Items to appear in future versions include new data elements. For example, collaboration with the FBI to ensure that NIBRS and N-Dex elements are part of the GJXDD is under way.

So how does one put a stake in the ground in order to have the latest work? The good news is that, much like a software product such as a word processor or a spreadsheet, in almost all instances, the work you do in one version will be compatible with future versions. What this means is that when your sister agency implements an RMS from vendor A, and then several months later you install a new RMS from vendor B, as long as both vendors have used the data model as intended, you will be able to exchange data without any worries about compatibility.

In order for any work to remain applicable, it needs constant feedback and growth. A focus group of practitioners and vendors, across a variety of disciplines, has been created to ensure that those responsible for the GJXDM are listening and improving upon the work. This effort brings together technical people who have actual experience with the GJXDM in order to ensure that the model continues to be relevant and useful.

Many vendors have introduced products that use the GJXDM, and many more have begun development efforts. A list of vendors committed to using XML and the GJXDM can be found at (, the Web site of the Integrated Justice Information Systems Institute, under the membership link on the left side of the page. If your favorite vendors are not on this list, encourage them to become involved in the Industry Working Group. This group is an excellent resource for vendors, helping them to understand and implement the GJXDM in their products.

Conforming to the Standards: One of the concerns foremost in the minds of law enforcement practitioners as they became aware of XML and the GJXDM was how to ensure that the GJXDM was included in their IT systems. Agencies wanted to make sure that vendors of their systems could conform to the GJXDM and that agencies include it in their requests for proposals (RFP). So the quest for the definition of conformance began.

The Dictionary: GJXDD
The GJXDD is a data dictionary and national reference model in the form of an XML schema, a framework that will be extended (or adapted) by state, local, and tribal jurisdictions to support their specific information exchange requirements and standards

The GJXDD is a work in process. The work to date has focused on consolidating and organizing approximately 16,000 terms used across a wide variety of jurisdictions into a vocabulary of approximately 2,700 terms.

GJXDD is not a standard. The initial effort was intentionally overly inclusive. That is, all possible terms were captured and duplicates removed, but no effort was made to define a core set of terms that all jurisdictions would use in the context of specific exchanges. These items will be addressed as the GJXDD matures over the next months and years, either by those involved directly in the GJXDD, or by organizations and jurisdictions themselves (for example, LEITSC is working to determine which reference documents are applicable to all law enforcement).

The GJXDD does not define interoperability. Instead, its terms, definitions and model schema can be used to enable interoperability.

How to Incorporate GJXDD into Your Procurement Documents
Procurement document references to GJXDD will do two things:

  • Clearly communicate to potential responders your decision to embrace GJXDD, explain to the reader why it is important to do so, and describe the context in which it must work
  • Establish a response mechanism that requires responders to explain their understanding of GJXDD, their proficiency with the reference model, their ability to incorporate related requirements and standards, and their commitment to demonstrate their proficiency and knowledge as part of the procurement process

To achieve those purposes, we suggest you include in your procurement documents (RFPs, for instance) the following information and requests:

  • A description of the architecture in which GJXDD will be used. If the procurement document includes a request for the definition or development of an architecture, a description of how the GJXDD will be incorporated into the proposed architecture should be requested.
  • Reference documents and standards by which GJXDD will be extended. If you do not already have the reference documents developed, a good place to begin is the OJP Web site (
  • Any planned development of reference documents and standards.
  • A request for narrative response that will confirm that the responder understands GJXDD, understands the context in which it will be used, and can actually demonstrate, if requested to do so, the ability to use GJXDD to exchange information and achieve interoperability.

It is equally important that the responder understands where you are in the GJXDD process. It will be necessary to include a narrative of what work has been done (if any) by your organization to prepare for the implementation of GJXDD. This narrative should include your related requirements, standards, reference documents and any other materials that will assist the responder in providing you with a relevant response to your proposal. If there has not been any preparation work done prior to the release of the RFP, this should be explained as well.2

What Not to Put in Your
Procurement Documents

Some of the requirements police agencies typically write into their information technology RFPs do not apply when it comes to GJXDD.

GJXDD Compliance: It would be premature to require vendors to be GJXDD-compliant. Because the GJXDD is not yet a standard, traditional compliance is not an appropriate measure. Instead, you can require providers adhere to the GJXDD reference model, and you can demand that they comply with associate reference documents and standards (when they exist). Providers can even help a jurisdiction develop reference documents and standards based on the GJXDD. But at this time they cannot "comply with the GJXDD."

GJXDD Certification: At this writing, there is no certification process for GJXDD. As the practitioner, domain, and industry communities continue work to define interoperability, a certification process could be developed. In the meantime, it may be more appropriate to have responders explain (either in their initial responses or in later qualification stages of the procurement) what methods and documentation they will use to verify adherence to the GJXDD data dictionary and reference model.

GJXDD Experience: Because GJXDD 3.0 was released January 2004 it is unlikely that many providers will have multiple implementations of such a new reference model. And it is impossible for providers to have had years of experience with GJXDD.

Sample RFP Language
Here is some sample language from an RFP. This certainly can be improved upon, but gives a general idea of how to phrase the GJXDD requirement.

    The ___ Police Department is committed to using nonproprietary technologies, open standards, and industry models throughout the project. These include, but are not limited to, the following:

    • ODBC-compliant relational database technology
    • TCP/IP-addressability of all components throughout the network
    • Global Justice XML Data Dictionary (GJXDD) - see (

    Offerors shall indicate the degree to which their currently available products are compliant with the first two standards and a description of the modifications, if any, that would be required to achieve compliance and target dates for completion of such modifications. In the case of the GJXDD, offerors must describe their proficiency with the reference model, their ability to incorporate related requirements and standards, their commitment to demonstrating this proficiency and knowledge as part of the procurement evaluation process, and their commitment to working with the center and the law enforcement agencies it serves to develop reference documents and standards based upon the GJXDD as needed.

What's Next for GJXDM?
Figure 1 illustrates how the GJXDM and associated tools can be used to build a schema.3 Many of the tools to achieve this vision are still in their infancy.

Multiple efforts in support of the GJXDM are under way, including development of the following products and services:

  • Tools for developers, users, and stakeholders that simplify the model
  • Training on the GJXDM, eventually to include remote or distance learning
  • Support structure (such as a help desk) to provide assistance
  • Outreach to other disciplines, such as transportation and public safety, that overlap our communities

Why Police Executives
Should Care about XML

For an executive with competing demands and priorities, it is often difficult keep up with the changes in technologies that affect law enforcement. In addition, the technical intricacies of XML make it even more daunting. But as awareness and use of XML grows, it is important to understand what work is being done, what are the trusted resources, and most importantly how you can exploit this technology to meet the goals of your agency, such as fiscal responsibility and officer safety through correct and timely information.

1 See the Department of Justice's Office of Justice Programs Information Technology Web site at ( The section named "Organizations Utilizing the GJXDD" gives examples of law enforcement executives' interest in GJXDM and GJXDD. The site will also link to the Justice Standards Clearinghouse (JSC), which lists many of the standards efforts that police departments can use.

2 See for more details about the Pre-RFP Toolkit, an excellent resource to use in building an RFP.

3 O'Reilly and Associates defines "schema" as "an XML vocabulary for describing the permissible contents of XML documents from other XML vocabularies."



From The Police Chief, vol. 71, no. 6, June 2004. Copyright held by the International Association of Chiefs of Police, 515 North Washington Street, Alexandria, VA 22314 USA.

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