Share Alike: AFIS Interoperability
Written by Kristi Mayo   

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ENTER ONCE, search many: That is the goal of professionals in forensic science who are engaged in an effort to establish inter-operability between automated fingerprint identification systems (AFIS) in the United States. The phrase refers to the ability for an examiner to seamlessly search a latent print against a local AFIS, state AFIS, neighboring state’s AFIS, and federal fingerprint repositories without the need to swap workstations or re-encode the latent print multiple times.

The concept of latent-print AFIS interoperability is not new. In fact, efforts to establish a standard for exchanging fingerprint data go back as far as 1986. Decades later, agencies and organizations still struggle to define AFIS interoperability, paint a complete picture of what that looks like, and determine the most efficient plan of action that will make it possible in the real world.

If anyone needed official confirmation of the importance of establishing AFIS interoperability, they received it in 2009 with the publication of the National Academy of Sciences (NAS) report, Strengthening Forensic Science in the United States: A Path Forward. In the report, the NAS committee wrote:

“There is no doubt that much good work has been done in recent years aimed at improving the interoperability of AFIS implementations and data-bases, but the committee believes that, given the potential benefits of more interoperable systems, the pace of these efforts to date has been too slow, and greater progress needs to be made toward achieving meaningful, nationwide AFIS interoperability.”

In the spirit of that recommendation, three government initiatives have come to the forefront in recent years to meet the looming challenge of AFIS interoperability:

Latent Print AFIS Interoperability Working Group—This working group, established by the National Institute of Standards and Technology (NIST) Law Enforcement Standards Office (OLES), features state, local, and federal representation from the latent-print community. Their goal is to determine what interoperability looks like, and to identify barriers that stand in the way of creating AFIS interoperability.

• Specifications developed by Noblis—The nonprofit research corporation, Noblis, is working with NIST and the National Institute of Justice (NIJ) to develop specifications designed to enable vendor-neutral latent AFIS interoperability.

• AFIS Interoperability Task Force—This task force, part of the White House Office of Science and Technology Policy, is working to establish both short-term and long-term goals that can solve the interoperability issue.

While each group works independently and examines overlapping but different parts of the interoperability picture, there is one common thread: Melissa Taylor, a management and program analyst at OLES. Taylor manages the technical working group, serves as program manager for the Noblis project, and is co-chair of the White House task force.

Before she came to the NIST OLES, Taylor was consulting to the NIJ’s forensic science program.

“While I was there,” Taylor said recently, “I was spearheading an initiative to create a working group that would help gain a better understanding of the barriers to AFIS interoperability. We understood there were some standards in place that were supposedly enough to fill in the gap. But people in the community were still screaming that this was a major issue. So we wanted to get an idea of why interoperability wasn’t happening. What were the remaining barriers that were seemingly insurmountable at the time?”

Painting a more complete picture

After Taylor moved to the OLES, NIST received approval to reestablish a Latent Print AFIS Interoperability Working Group. Taylor said the working group spent the first year and a half of meetings determining whether interoperability was truly a problem.

“This is because there is a certain level of interoperability that agencies already have at this point,” Taylor explained. “For example, many local agencies have the ability to search their local system, then their state system, and then the Integrated Automated Fingerprint Identification System (IAFIS).”
This kind of search structure—referred to as a vertical search process—is familiar to most agencies, but it is not true interoperability. Often, running progressive searches on local, state, and federal systems requires the examiner to change workstations and re-encode the latent image.

Further, the ability to initiate searches to neighboring local agencies—called a horizontal or peer-to-peer search—is nearly non-existent. There are a number of roadblocks that stand in the way of agencies sharing their fingerprint information… and the working group has made an effort to identify those roadblocks.

“Some are technical, some are financial, but a lot of the issues stem from inadequate planning,” Taylor said. In other words, even if two agencies know that they would benefit from the ability to search each other’s AFIS systems, they may not know what to ask for.

And knowing what to ask for, says Taylor, may be one key to unlocking interoperability.

Ask and you shall receive

From the time that agencies began to implement automated fingerprint databases in the 1980s, differences have flourished. Each state—and every agency within those states—may have a slightly different set of standards and operating guidelines. The existence of multiple AFIS vendors means a variety of proprietary methods of noting and extracting features in a latent image. Even if two agencies use the same AFIS vendor, they may not have the same build of software. And then there is the procedural framework that each agency establishes when they set up an AFIS: technical, administrative, and legal requirements that must be carefully spelled out and adhered to.

All of these differences may seem impossible to overcome, but the Latent Print AFIS Working Group has produced a set of tools intended to help agencies know what to ask for when procuring a new or updated AFIS, and how to work with other agencies when setting up agreements to share fingerprint data. The tools, called Writing Guides, will be available online this fall.

• Writing Guide: Proposal Development—This document “walks an individual through all of the different questions that need to be answered in order to procure systems that meet standard specifications,” said Taylor. This includes writing a Request for Information (RFI) for vendor contribution, producing a Request for Pro-posal (RFP), and selecting a winning vendor to provide an upgraded or new system. As Taylor explained, the working theory is that if all agencies begin to ask vendors for the same capabilities and standardized technology, more systems will become interoperable.

“It comes down to what the market wants,” said Taylor. “If you ask for it and you pay for it, then you’ll get it. The trick is to know what to ask for.

“Without guidelines, you might have two agencies that create a standard that works for them, and then another two agencies create a standard that works for them, until you have these ad-hoc standards popping up. The Writing Guides are designed to help agencies adhere to one standard. Then, no matter what, everyone will have the ability to communicate with each other, technically. The next step, of course, is to work out the Memorandums of Understanding (MOUs) in order to actually be able to start doing the searches.”

• Writing Guide: Memorandum of Understanding—The MOU is an agreement between an agency that maintains an AFIS (the hosting agency) and an agency that seeks to access the system (the requesting agency). The MOU Writing Guide helps agencies determine specifications such as times and volumes of searches that will be allowed to requesting agencies, legal requirements, hold-harmless clauses, and other agency-specific variables.

The Writing Guide also “identifies the appropriate players who need to sit around the table and help answer these questions—so it’s not just AFIS manager talking to AFIS manager,” said Taylor. “You also need to bring in your legal advisors and your IT consultants, so you will have all the different nuances of an agreement worked out up front.”

The Writing Guides are formatted so that they can be used as a general guideline—providing the outline, reason, and logic for what needs to be written. Or, they can actually be used as templates, offering sample language that can be directly copied into an agency’s own MOU or RFP. “They do have that level of specificity, if you need it,” said Taylor. “We are not forcing the template on anyone. They can read the Writing Guide and come up with their own language if they want to—but if they like the language that’s in the Writing Guide, then they are free to use it.”

Building a technical foundation

Traditionally, AFIS vendors have created their own methods of encoding a latent image. As a result, latent-print examiners must work with slightly different AFIS interfaces when attempting to search on multiple systems—such as their local AFIS and IAFIS, for example.

“How you mark a ridge ending on one system may not be how you mark a ridge ending on another system,” explained Taylor. “And there may be rules, such as one system requiring you to mark close to the core. Another system may require you to count the number of ridges between features. And none of those markup features are standard between vendors.”

The end result Taylor likened to a computer user who frequently switches between a PC and a Mac. Keystrokes, shortcuts, and commands of the two systems differ enough to cause a hiccup in the user’s mind.

“So, we need a way to mark up a latent print one way so that the different vendors would be able to extract what they need in order to conduct their searches,” said Taylor.

With that in mind, several efforts are being made to develop standards for the encoding and exchange of latent-print images.

A key result of this effort is being rolled out with the 2011 update to the ANSI/NIST-ITL Data Format for the Interchange of Fingerprint, Facial, and Other Biometric Information. New to the 2011 ANSI/NIST-ITL standard is the Extended Feature Set (EFS), a standard method of characterizing the information content of a latent-print image.

“The EFS standard allows a common language to be used when encoding a latent print, so that examiners many years from now will know what was meant,” said Bradford Wing, biometrics standards coordinator with NIST. “That’s a major advance in the area of fingerprints.”

The EFS covers all friction-ridge images, including fingerprints, palm prints, and footprints. It includes an extensive and technical list of capabilities for the latent-print examiner. “You can actually mark out on the print itself a ridge-flow pattern. You can do a tracing of the ridge-flows. You can mark out minutiae, where the ridges bifurcate and end. And you can also include areas to be specifically compared against the exemplar print,” said Wing.

The voting to adopt the 2011 ANSI/NIST-ITL standard closed on August 31, 2011 with four No votes. Concerns submitted with those No votes were addressed, and it was put out for a 30-day recirculation ballot that closes October 11. At press time, the vote was a unanimous “Yes” and the standard would be adopted after the close of the voting period.

“There are several AFIS vendors that are already developing the capabilities to use the EFS,” said Wing. “This is not a ‘must comply’ measure. But if the vendors want to build in the capability to offer the EFS, they will need to follow these standards to be able to report out the data that users are generating using their equipment.”

Meanwhile, another organization is already utilizing the EFS to generate additional standards to enable interoperability. Noblis, the nonprofit science, technology, and strategy organization, has contracted with NIST to develop three technical specifications:

• Latent Interoperability Trans-mission Specification (LITS)—The LITS defines the format of the information that is provided when two AFIS systems exchange latent-print data.

“In order for interoperability to work, one system has to know how to send the information in a standard format, and the other system has to recognize that format when the transmission is received,” said Taylor. “The LITS sets up the language that two systems are going to use to communicate with each other.”

• Extended Feature Set Profiles—This specification defines the set of EFS fields that will be used in latent-print AFIS searches.

• Extended Feature Set Markup Instructions—This specification lists a set of definitions and best practices for the markup of vendor-neutral fingerprint and palm-print features. The common language in the instructions would be utilized by latent-print examiners as well as manufacturers of AFIS systems.

The establishment of all of these standards and guidelines sets up agencies to realize interoperability between AFIS systems, increased examiner efficiency, and reduced time and cost associated with training.

“You would be able to train an examiner once, because no matter what system they are using or what agency they are working at,” said Taylor, “they would be trained on these universal standards.”

Tying it all together

The final effort currently being made toward AFIS interoperability is the AFIS Interoperability Task Force. “The task force is looking at ways to encourage the adoption of different standards, and to identify gaps in current standards,” said Taylor. “For example, security standards: Even if we get the agreements down and we have the technical know-how in place, we still need to be able to securely transmit the data from one point to another.”

Other questions that the task force is working to answer include: “What kind of network are you using to send the data?” asked Taylor. “Are you sending it encrypted over the Internet, or are you sending it through a secured FTP site? Also, how can we leverage the existing infrastructure—such as possibly utilizing the CJIS-WAN (wide area network), or other networks that are currently in place—to facilitate interoperability?”

“They are looking at these issues on a national level, and seeking to learn what federal investments can be used to help state and local agencies search each other more seamlessly.”

What you can do today

The picture of interoperability has yet to be completed, but, according to Taylor, there are a few steps that state and local agencies can take now to move toward that ultimate goal.

First, users can visit the Noblis website to review and provide comments on the draft documents for the LITS and EFS profiles and markup instructions.

Also, agencies can start by making sure their AFIS systems transition to the new standards for interoperability as soon as possible.

Taylor suggested this could be achieved by using the Writing Guides the next time your agency’s AFIS is due for a full system overhaul.

“Every seven to ten years, agencies might go out for a full bid,” said Taylor. “As people procure new systems, they will be able to make sure that their new systems adhere to these new standards.

“This is not going to be an over-night fix,” she added. “But the first part is making sure that you have the technical capabilities to send and receive the data in a standard format.”

For more information

The Writing Guides produced by the Latent Print AFIS Interoperability Working Group can be accessed at:

The draft documents for the standards being developed by Noblis can be found at:

To review the 2011 ANSI/NIST-ITL standard, go to:

About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is the editor of Evidence Technology Magazine.

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