RFID In Forensics: What is it and what will it do?
Integrated RFID solutions can provide all the software and hardware needed to develop and keep an electronic chain-of-custody from the crime scene through the courtroom.
Radio Frequency Identification (RFID) technology has been used for many years for many types of applications. If you drive a car less than 20 years old, its key has a small microchip that identifies that specific key as the only one authorized to start your car. Other common uses of the technology include paying tolls without stopping, getting into facilities with only a badge wave, paying for goods with a credit card wave rather than swiping, and retail item theft detection systems.
What is RFID?
RFID is a generic term for technologies that use radio waves to automatically identify individual items, their location, transaction, and time, quickly and easily without human intervention or error. Several methods of identifying objects using RFID exists today, but the most common is to store a serial number that identifies a product, and perhaps other information, on a microchip attached to an antenna, which enables the chip to transmit the identification information to a reader. The combined chip and antenna, commonly called an RFID transponder or an RFID tag, is the core component of an RFID system.
Each RFID tag carries a unique identifier, in addition to having memory up to 64,000 bytes which can be used for client applications. RFID tags are broken into three categories or types, each with its benefits and limitations:
- Active RFID - Long read range, expensive, limited life battery (assists in transmission to reader), active transmitter, optional sensors.
- Passive RFID - Short and medium read range, inexpensive, long life, powered by reader only, and backscatter data “transmission”.
- Battery assisted passive - Similar to passive; slightly longer read range, limited life battery (microchip remains powered from battery).
The reader provides RF power to tags via antennas. They convert the radio waves returned from the RFID tag into digital data that is passed on to computer software for analysis and storage. Major benefits include the ability to read all nearby tags almost simultaneously such as reading tags as they pass by on a conveyor belt or as they pass through a doorway. Readers do not need line-of-sight and can read tags through non-metal walls. In addition, they can be hand-held or stationary and may support multiple antennas. An antenna is a conduit between a tag and reader, which emits and receives radio signals to activate and communicate with tags. Many different forms of antennas exists to accommodate various applications. The Portal System is incorporated to track items as they move in or out of a facility, throughout a facility, or through multiple facilities. Specifically, they are designed to do the following:
- Divide a building into compartments/zones.
- Locate items in evidence storage rooms, between departments, or all entrances/exits.
- Detect the directionality of items moving throughout the facilities.
Handheld Units are utilized to identify items stored in an RFID system on a mobile platform. This offers portable reader capabilities fully inline with the fixed version of the software. The handheld units have the abilities to read both barcode labels and RFID labels and the wireless interface allows the handheld devices to integrate with the information stored in an enterprise RFID system. Handheld devices locate items rapidly and at great distances. The remote data input capabilities allow the establishment of an electronic chain-of custody of items from the point that they are commissioned.
RFID Enabled Smart Tables contain embedded RFID readers and antennas that are capable of RFID and bar code scanning. These tables can be used for accessioning evidence or during chain of- custody transfer and reading hundreds of items in seconds. The Smart Table interfaces with RFID software that integrates into LIMS or case management software to initiate the tracking of evidence.
RFID Enabled Printers apply the RFID coding and print a barcode label that can both be tied into the RFID software and the LIMS. The RFID chip on the tag is aligned properly, so that as it passes through the printer, the information is electronically written to the RFID tag. The information on the tag is verified immediately. After printing, the tags are placed on the individual items so that they can be tracked.
The last essential, and most important, element of an RFID system is the Software. The software is designed to manage the process where the RFID tags will be used for identification. The software ties all of the information associated with an item to the RFID tag. The details are provided below on managing the collection of evidence, accessioning, chain-of-custody transfers, and locating items.
RFID Benefits versus Bar Code:
Bar code requires labels to be “seen” by lasers. A direct line of sight is required to read a bar code. This “point and shoot technology” is time consuming when compared to RFID. Since radio frequency identification does not rely on visual alignment to gather information, product can also be randomly placed on a pallet or in a warehouse. RFID technology enables tag reading from a greater distance, even in harsh environments.
- Information imprinted on a bar code is fixed and cannot be changed. Some RFID tags, on the other hand, have electronic memory and can be dynamically updated.
- Deliberate vs. Automatic Scan:
•Whether at a checkout or in a warehouse, bar codes are read deliberately by a person with a scanner.
•An RFID tag automatically announces itself to a nearby reader by means of its radio signal. The continuous stream of data available with RFID technology will increase accuracy and reduce the costs of inventory control.
- RFID Advantages compared to Bar codes:
•No line of sight requirement.
• The tag can stand a harsh environment.
• Long read range is possible.
• Read/write multiple tags simultaneously.
• Can track tagged items in real-time.
RFID technology can assist in the forensics process from the collection of evidence through to presentation in the courtroom. Using, RFID tags, readers, portal systems, handheld units, SmartTables, printers, and software developed specifically for the chain-of-custody requirement needed by law enforcement agencies, data can be easily collected and integrated into LIMS or case management system software. Data can be entered into a handheld device and linked to evidence collected at a crime scene. Since this data can be integrated with other software systems, the data collected electronically at the crime scene does not require reentry and risk transcription errors. This process can be further simplified by using crime scene collection kits pre-labeled with RFID tags.
Evidence Collection at the Crime Scene
Labeling evidence and creating a manifest of collected items manually takes a lot of time and is subject to transcription errors. New handheld devices and software that are designed to capture basic case information and automatically create an electronic manifest of items collected are now available. The handheld devices work with crime scene collection kits pre-labeled with RFID tags or with evidence that is tagged at a crime scene with an RFID tag to create an electronic document capturing case information at the crime scene. This eliminates the need to transcribe the information into a case folder saving a lot of time and potential transcription errors. Labeling evidence with an RFID tag at the point of collection also improves the security of evidence since it is easier to track with RFID technology.
When the collection process is complete the case information and evidence manifest is transmitted to your agency so the case and sample information will already be in the system, significantly reducing accessioning time to a few seconds.
This also creates an electronic chain-of-custody that begins at the point of collection and is tracked through the lab and to the court room.
As samples are received in the evidence room, they pass through an RFID-enabled portal that identifies each item by reading the RFID tags as they pass through. As the items are handed off, the RFID enabled badges of the person delivering the package and the evidence custodian are read—creating a chain-of-custody transfer automatically by recording the identification of each person, the time, and items transferred.
When case information is transmitted to the agency and stored in the case management system before the evidence arrives, the accessioning process is completed by putting the evidence on an RFID reader or an RFID enabled Smart Table that will pull up the previously transmitted data from the crime scene and compare the data to the evidence it is reading. If the data is identical, including all evidence collected and received, the accessioning process is complete and chain-of-custody confirmed. If there are any discrepancies they are identified for further troubleshooting.
There is no need to open any evidence packaging for this process since RFID tags do not require line of sight to identify the tag and evidence. At this point the evidence custodian can either store the evidence as required or redistribute them to the lab for testing. The RFID system eliminates much of the bottleneck in the accessioning process.
If the items are being stored, their location is entered into the RFID software. This can be done manually, through RFID enabled storage facilities or with an RFID enabled handheld device.
Sample Retrieval and Chain-of-Custody Transfer
When the laboratory is ready to process a sample or if the sample needs to be transferred, they are located using the look-up feature in the RFID software. If the sample has been moved or is not in the identified storage location, a handheld RFID reader can be used to search for the specified sample. As the sample comes into range of the reader (up to 15 feet away), an audible beeping is emitted and the beeping becomes louder and more frequent as the reader gets closer to the item. This feature significantly reduces time spent looking for items.
As samples are received into the evidence room, they can be accessioned by using an RFID enabled Smart Table. A Smart Table automatically reads and creates a manifest of all items being accepted or transferred. Smart Tables read multiple items at a single time without needing to see the label (which would be necessary if using barcode labels). A Smart Table can also be used as a chain-of-custody transfer station. As items are read, so are the RFID badges of the individuals transferring the items. By a click of a button, custody is transferred and a log is created.
Tracking Through Facilities and Alerts
Portals throughout a facility allow items to be tracked within zones. As items pass through the portals, their location is automatically tracked and stored in the RFID software. As these items move through the facility, the RFID-tagged badges of the personnel carrying the items are read as well. As the badges and items are read together, the items are associated with the individuals and the custody is verified. Motion detectors are used to determine the directionality of the movement and record if items and personnel are leaving or entering a zone in the RFID software.
If items or personnel enter unauthorized areas, the system can be programmed to make a visual and/or audible alarm which alerts the personnel with the items and administrators monitoring the system.
Tracking Case Folders
RFID systems can track all items and assets including case folders using the portals throughout a facility. The location of the case folders detected are logged into the RFID software. Case folders can then be located within a zone using the Find and Locate feature of the reader as noted above.
RFID is a proven technology with commercial applications that date back to the 1960s. RFID makes it possible to automate manual tasks such as creating an evidence manifest and accessioning items into evidence storage. Integrated solutions are available to provide all the software and hardware needed to develop and keep an electronic chain of- custody from the crime scene through the courtroom. Much time can be saved in the accessioning process or looking for lost items like case folders. RFID has become a cost-effective solution to improve the efficiency of the forensic process.
Randy Nagy has worked in the DNA identification field for more than 20 years. He is a member of the IACP Forensics Committee and serves on the Technical Working Group on Biological Evidence Preservation. Mr.Nagy earned his bachelor’s degree in biochemistry at the University of Western Ontario.
Andrew Singer is the Senior Product Manager at Bode Technology. Mr. Singer has been involved in product development and management for six years in the biotechnology and forensic fields. Mr Singer earned a Masters of Business Administration and a Masters of Science degree in Biotechnology from John Hopkins University and a Bachelors degree in Chemical Engineering from the University of Maryland.
Gordon Fraser is a versatile RFID Subject Matter Expert and Innovation Specialist with over 20 years of technical, managerial, and business development. His technology activities extend back to 1983, although he has been working consistently in the RFID field for the last 10 years. Much of his work has involved developing hardware systems needed for specific applications and testing all aspects to ensure operational capability and reliability.
Bode Technology has developed the Bode-RFID™system which has software specifically designed to manage forensic processes. The Identi- Gun™ has software to manage the collection of evidence at a crime scene as well as the ability to help locate evidence in an evidence locker or casework folders in an office. The Bode-RFID™ system handheld software that is part of the Identi-Gun™ or the server software both have an effective chain-of custody function that simplifies the transfer of evidence from one owner to the next. The software also works with the SmartTable™ to simplify the accessioning process. Working together with Bode RFID-tagged collection kits or RFID tags applied by the user, the Bode-RFID™ system creates an electronic manifest of items collected at the scene and simplifies the evidence collection process. Additionally, Bode Technology offers the Bode-RFID™ system software, all the portals, readers, antennas, SmartTables, Identi-Gun handheld reader, and RFID tags needed to manage all forensics processes.