Radio frequency identification (RFID) tags--devices that can transmit data over short distances to identify objects, animals or people--have become increasingly popular for tracking everything from automobiles being manufactured on an assembly line to zoo animals in transit to their new homes.

Now, thanks to a new NIST report, the next beneficiaries of RFID technology may soon be law enforcement agencies responsible for the management of forensic evidence.

A typical RFID system consists of a microchip programmed with identifying data--the "tag"--and a two-way radio transmitter-receiver, called an interrogator or a reader depending on its use. The tag can be attached or embedded in the item to be tracked, with the radio either sending a signal to the tag or reading its response.

Common examples of RFID systems include the FasTrak and E-ZPass in-car tags for automatically collecting tolls, tagged prescription drugs that help pharmacies meet federal and state safety regulations, and credit cards with embedded RFID chips that provide a more secure way of transmitting card numbers than magnetic strips.

RFID systems can read hundreds of tags in a few seconds and track an item as it moves through a process. More advanced RFID tags can sense and report on environmental conditions, or encrypt the data they send.

While some law enforcement agencies have used barcodes to improve their forensic evidence tracking, storage and retrieval processes, very few have implemented RFID because of concerns about startup costs, the reliability of the technology and the current lack of relevant RFID standards for property and evidence handling.

To help agencies better understand these issues and properly assess the pros and cons of RFID evidence management, NIST recently published RFID Technology in Forensic Evidence Management, An Assessment of Barriers, Benefits, and Costs.

The report is the result of a NIST-funded study on automated identification technology (AIT). The Technical Working Group on Biological Evidence Preservation, cosponsored by NIST and the National Institute of Justice (NIJ), commissioned the study and report.

The NIST report includes a helpful overview of AITs--focusing primarily on RFID and barcode technologies--and how they work. It describes, in depth, the types of RFID systems available (passive, active and battery-assisted), their price ranges, and the components necessary for a complete system. The report also details the barriers that agencies may encounter, followed by a series of successful RFID management case studies, including examples from the pharmaceutical and retail industries, and one law enforcement agency that has made the switch, the Netherlands Forensics Institute.

The practical question that agencies must consider--and one that the NIST report can help them answer--is whether RFID technology can produce measurable benefits and a positive return on the funds invested in a new system. The NIST report estimates that RFID systems can pay back their initial set-up cost in about two years.

Various factors can affect the payback period. For example, systems that track and manage larger inventories of evidence (100,000 or more items) will recoup costs more quickly than those handling smaller inventories. However, if multiple jurisdictions share the costs of a system, the payback period can be shorter.