Travis County Fire Marshall Uses RFID to Manage Evidence

Evidence arriving at the Travis County Fire Marshall's office falls in two categories: high-security items such as DNA, rape kits, drugs, guns and money; and low-security items such as bicycles and clothing that are neither likely to be stolen, crucial to the case, nor expected to be returned to the original owner. The high-security items require a higher level of tracking, so the agency is employing 433 MHz RFID active tags to alert personnel as soon as such items are moved. Others, tagged only with EPC Gen 2 UHF passive tags, will transmit an alert only if removed from the office.

When an item—regardless of its security level—is brought into the office as evidence, the staff assigns it a case number and inputs a description of that evidence, as well as the date and time of arrival, into a back-end system. Employees use a Datamax RFID printer to print and encode an EPC Gen 2 UHF passive label with a unique ID number. A staff member applies the RFID tag to the item and reads it with a handheld MC 9090 Motorola interrogator, linking the tag's ID number to the case number and a description of the item, as well as the date and time it was processed. High-security items are also given an RF Code 433 MHz active RFID tag, and the active tag's ID number is entered into the back-end system as well.

Tate Markey

The back-end system and all data are hosted on a Web-based server operated by Rack Space, enabling the information to be located in several geographic locations. In the event of a natural disaster, for example, the data would not be lost, as it was in some courts in the New Orleans area following Hurricane Katrina.

If Travis County workers remove an item from the evidence room, they use the handheld RFID interrogator to read its EPC Gen 2 tag and input details indicating where the item is going and who is taking it there. If the item is removed without approval, the fixed RFID reader at the exit will capture the tag's ID number, as well as the direction—in or out—in which the item is being taken, then transmit an alert via e-mail to Calloway and Markey's BlackBerries. If a high-security item is moved in the evidence room, the 433 MHz RF Code interrogator sends a similar alert to both of them.

The system also helps the department manage its archived material, Markey says. At the end of the 10-year statute for a specific case, he explained, the Clues software sends a message indicating that archived evidence related to that case can be destroyed.

The agency began installing the system in late 2007. During that time, the county was moving its evidence room to a larger office 15 miles away, and using the fixed UHF RFID reader, temporarily installed at the first office, to track when evidence departed one location. It then installed the reader at the new site, where it scanned evidence again as it arrived.

In the future, Calloway said, the office hopes to use RFID tracking for other purposes. The fire marshal's staff works in the same building as the county's Office of Emergency Management, he noted. In the event of a hurricane or other disaster, RFID tags could be employed to link evacuees with their pets so that if they became separated during temporary housing, they could be reunited by capturing the identical ID numbers on their tags. Calloway said he would eventually like to expand the system to allow the attaching of labels to evidence while still at the crime scene, before it reaches the evidence room.