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Evidence Management Tracking: RFID vs. Bar Code Technology

May 15, 2019

If you are in charge of a property and evidence room, RFID is knocking at the door as a potential evidence management solution. Radio Frequency IDentification is a technology that already has an impact on most of the things you do on a day to day basis.

Wikipedia describes RFID as: An automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. An RFID tag is an object that can be attached to or incorporated into a product, animal, or person for the purpose of identification using radio waves. All RFID tags contain at least two parts. The first is an integrated circuit for storing and processing information, modulating and demodulating a radio frequency (RF) signal and perhaps other specialized functions. The second is an antenna for receiving and transmitting the signal. The RFID tag can automatically be read from several meters away and does not have to be in the line of sight of the reader. The current thrust in RFID use is in supply chain management for large enterprises. RFID increases the speed and accuracy with which inventory can be tracked and managed thereby saving money for the business.

evidence management

My favorite potential solution is one that is still in the works. Imagine that you go to the grocery store one day and bag your own items as you walk through the store. When you head to the checkout, you simply run the cart under a scanner and it instantly knows the exact sum of the prices for all the items in your cart. Checkout lines will go from a 10 to 15 minute wait, in some cases, to less than 30 seconds. This will only be possible when every item in every store contains an RFID chip. further explains “One of the key differences between RFID and bar code technology is RFID eliminates the need for line-of-sight reading that bar coding depends on. Also, RFID scanning can be done at greater distances than bar code scanning. High-frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer transmission ranges of more than 90 feet”.


RFID received a major boost when Wal-Mart and the Department of Defense mandated that every item from every vendor contain one of these unique RFID labels. This technology makes perfect sense for Wal-Mart. Why unpack a truck full of goods to get a count on each item when you could run the truck through a scanner and get an accurate count on the items in that truck. You can imagine how much time this saves in the shipping process.

The primary purpose of RFID is to reduce the amount of time that it takes to perform a transaction. In the examples above you can imagine how much time it saves in performing any one of those functions.

Now for the big question: Does RFID have a place in the evidence room? I would state that it does not, but you need to understand the plusses and minuses in order to come to your own conclusion. Bar-coding, much like RFID, is meant to speed up the process of performing transactions on an item. As stated earlier, the drawback to bar-coding is that line of sight is required to perform a transaction on an item. The primary reason for implementing RFID is to remove the line of sight requirement, thus allowing for faster processing. Processing 50 items with a bar-code reader could easily take 3-5 minutes, but RFID will complete the same transactions in 3 seconds or less.

evidence management

The following evidence management processes are currently able to be completed with a bar-coding solution. • Chain of Custody (Check In / Check Out) • Disposition • Move • Audit • Security

If you currently use a bar-coding system for tracking your evidence, you understand how bar-codes facilitate your use of the evidence management system. It is very important to understand what a bar-code does because RFID is touted to be a superior replacement to the bar-code in these key areas.

I am a proponent of RFID, but in the evidence room there are some real problems with an RFID solution. First and foremost, in the evidence process, line of sight of an item or tag is critical. Accuracy is paramount to speed. For example, an officer comes to you and wants to check out 50 items for court. You retrieve the box from the shelf and give it to the officer. Are you going to check out each item one at a time and review each item or are you going to wave an RFID reader over the box and assume that the contents of that box are correct? When you check out those items it should be your intent that the items being turned over are accurate and listed correctly. You can only get an accurate listing when you have viewed each item being checked out. The bar-code solution forces you to scan each item one at a time and in doing so, inspect each package. At the very least you will know if a package has been tampered with. The point of RFID is to remove the line of sight and consequently the accuracy in your check-in / out is diminished. There is simply no way to use RFID to check an item in or out if one of your requirements is accuracy. Bar-coding is a much better solution in this area.


Let’s move on to disposition. Disposition is much like a check out, but with disposition the items are not coming back. However, accuracy is no less important in this process. It is extremely important that each item being checked out for disposition is accurately documented in the evidence management system. You would not wave an RFID scanner over a box of items that is marked for disposition and rely on the fact that the scan is correct. You would individually inspect each item to make sure that the right case and item number is properly being disposed of. Bar-coding is a much better solution in this area.

Moving an item would be much easier with a RFID solution. Since the item is moving from one location to another in the same room and the transaction is being performed by a person with access to the evidence room, one could argue that the same level of accuracy would not be as important as the time in which it would save to perform that transaction. In this instance, the RFID solution has an edge.

evidence management

Next is the inventory process. Our polling has shown that well over 50% of police departments do not perform a routine inventory on their items with lack of organization being the primary reason given. So how can an RFID solution help in this area? The Book by Lt. Joseph Latta of IAPE describes an inventory as “individually checking all or a specified portion of the property items against the agency’s records. An integral part of the inventory process is to ensure that all items of property are accounted for. A complete inventory involves matching each piece of paperwork with its corresponding piece of property.” So my question would be this: how can you perform a full inventory unless you are physically inspecting each item? The short answer is that you can’t perform a full inventory with RFID. However, RFID does have a function in this area. If all of your items are inventoried with an RFID label, you will be able to easily perform a spot check on a group of items. In seconds you could inventory every item in a gun locker. Individually scanning each of these guns could take 5 minutes on 100 items whereas an RFID scan could be done in seconds. If you are performing a spot check and not a full inventory, RFID will certainly speed things up. However, in the end, bar-coding wins in this area.


Let’s now focus on some areas where RFID can have an impact that bar-coding cannot. Bar-codes are a stagnant print on a piece of paper and only have a purpose when being scanned. RFID labeling can have a pretty big impact even if it is not being used for a check-in / out, disposition or inventory. Security is certainly one of those areas. If you were to purchase RFID readers for the entrance to your evidence room, you would then know which items are coming in and out of your evidence room. Of course, one would have to assume that the RFID reader correctly scanned all of the items. That information could then be used to notify an administrator that an item is coming in or out of the evidence room. Bar-codes simply do not allow this to happen.

It all comes down to this: when dealing with drugs, guns or money, you need to be as accurate as possible, if not absolutely accurate. Your job may depend on that accuracy. You simply cannot allow for any errors in the evidence management process. The lure of speeding up the transaction process cannot be allowed to trump the need for doing things properly. RFID dominates the warehouse and manufacturing process because some level of inaccuracy is worth the time being saved. If you go back to the grocery store example, there is going to be inaccuracy in that environment. There is no doubt that the scanner may miss an item or two. However, the grocery store is willing to accept that loss because the process is much quicker and staff needs are reduced to complete your checkout.

Unfortunately, at this point in time there are more questions and problems than answers and solutions when it comes to RFID in your evidence room.  We hope you found this post about RFID vs Bar Code technology helpful in your search for the best evidence management system for your needs. Feel free to contact us with any questions about SAFE, and don’t forget to take advantage of our free evidence management comparison worksheet. Protection Status