In the March/April issue, the first installment of the two-part series “Cellular Contraband: Search or Destroy?” provided information on the use of cell phone jamming technology to mitigate the growing problem of contraband cell phones in correctional facilities. Next, we look at cell phone detection technology, alternative strategies, operational issues and cell phone forensics tools.
Cell phone jamming technology — currently illegal for all individuals and organizations other than the federal government — interferes with cell transmissions and blocks calls from being made or received. Conversely, the proven technology of cell phone detection identifies the existence and location of a cell phone while it is turned on, whether or not a call is actively in progress at the time.
Presently, the deployment of cell phone jamming technology is not an option for correctional agencies. The absence of legal restrictions on the use of detection technology make it a potentially viable tool in the battle to defeat contraband cell phone use.
Cell phone detection technology is relatively straightforward. All cell phone detection systems utilize essentially the same technology to detect radio frequencies emanating from a cell phone transmission or call. While most detection systems on the market can detect the GSM and CDMA spectrum signals, which are most commonly used by cell phone carriers, only some detection systems are able to detect the iDEN signals used by several other carriers.
Cell phone detection systems operate through the use of a series of sensors that are installed in an area of concern, ideally in hidden areas throughout the inmate housing units or cells. The system is controlled by a centralized computer that analyzes the signals identified by the sensors to determine the location of the cell phone.
A single sensor can detect a cell phone transmission within a range of approximately 50 feet to 100 feet inside a building and about 300 feet in outdoor locations. Given this range, multiple sensors must be installed to cover the entire area of concern.
In addition, the accuracy of the system can be affected by building construction, configuration and structural elements, as well as the orientation of the cell phone user in relation to the cell phone antenna. Such factors dictate that the more sensors there are installed in the target area, the more accurately the system will be able to pinpoint the precise location of a cell signal.
Cell phone detection technology offers a number of benefits that aid in reducing the flow and use of contraband cell phones. First and foremost, detection allows staff to locate and confiscate the contraband phone. The system provides real-time automated alerts of cell phone activity that allow quick staff deployment to the specific search location, which enhances the probability that the phone will be recovered and the perpetrator identified.
The monitoring and recovery of the phone, and the call information it contains, can result in the interception of valuable intelligence for prosecution and the prevention of criminal activity.
While there are numerous benefits to the use of cell phone detection technology, the single most glaring, and perhaps only real, impediment to implementation is the high cost of system deployment.
Deployment cost is affected by the complexity of the installation process and the quantity and cost of the individual sensors. A single-sensor device can cost approximately $500. In the case of a 2,000-bed facility with the goal of isolating cell signals to specific cells, the sensors alone, excluding system installation costs, would carry a $1 million price tag.
This scenario does not deliver full-facility coverage, as this estimate does not cover detection devices for general areas such as housing common areas, libraries, recreation areas, program space, dining halls, etc.
Given the constraints associated with cell phone jamming and detection technologies, many correctional agencies have explored the use of alternative solutions to combat the growing problem.
One such non-technological strategy involves the use of K-9 units specially trained in the detection of cell phones. Phone-sniffing dogs are trained to detect the scent of the cell battery rather than the phone unit itself.
While K-9 units have proven successful in many facility types and jurisdictions throughout the United States, the use of canines has some limitations. The strategy is extremely labor intensive to deploy and requires many hours of development training both for the dogs and the handlers. The dogs must be in close proximity to a phone in order to detect it, and the dog’s ability to effectively perform this function can be impaired by factors such as heat and fatigue.
Dogs are typically used when authorities have a suspicion that cell phones are in a general area, and therefore they are primarily a response to rather than preemption of a problem. While there are some drawbacks, the use of K-9 units can be a viable and effective intervention to reduce the flow of contraband phones.
One technological solution being used as an alternative to cell phone jamming or detection technologies is non-linear junction technology, which was specifically developed for counter-surveillance operations.
Non-linear junction devices detect circuitry boards in electronic components and were originally developed as a room-clearing technology to sweep for covert listening devices hidden inside walls, fixtures or fittings. The technology can detect various nuances, which is quite useful for counter-surveillance purposes. However, in correctional settings, the additional information identified by the devices is typically not relevant.
Additionally, because all cell phone circuitry boards contain some metal, inexpensive hand-held metal detectors can prove as efficient as a $13,000 non-linear junction device. In fact, while non-linear junction devices will detect cell phones, they will also detect electronic components in everyday/authorized items, such as clocks, radios and hot pots. Finally, the effective use of linear junction devices requires a high degree of training, in contrast to the minimal training required for inexpensive handheld metal detectors.
Body-scanning chairs and specially formulated paints and coatings that block RF signals are also currently being utilized as alternatives to cell phone jamming and detection technologies by some jurisdictions. However, the effectiveness of such strategies is scenario driven, with limited occurrence to justify the high cost.
Now, what do you do with the cell phone once you find it? As large numbers of cell phones continue to be confiscated, we must not forget the intelligence they can potentially provide, such as the numbers the inmates called, the phone numbers that were used to call the contraband phone, all text information, photographs, video, and dates and times. Currently, retrieval of this information is being overlooked by many corrections agencies.
Telephone forensics is a rapidly growing field that offers many low-cost tools to retrieve valuable intelligence. Tools range from $500 to $10,000 and typically require two or three days of training, depending on the complexity of the equipment. There are many training courses readily available to correctional and law enforcement agencies, some of which are free.
Regardless of whether an internal investigation is conducted or if the evidence is turned over to outside law enforcement, there are basic steps that must be taken immediately to maintain the integrity of the evidence and its forensic value. Most important, never turn off the phone, always keep the phone charged, and do not remove the SIM card.
I recommend purchasing a telephone forensic recovery bag, which prevents the phone from receiving calls pending forensic evaluation. If a phone is recovered and the inmate is able to contact someone on the outside, that individual can eliminate a great deal of the phone’s information or lock the memory, which makes it much more difficult for investigators to retrieve information. Additionally, most of the larger forensic tool companies will provide, free of charge, a list of “dos” and “don’ts” when recovering a cell phone.
I’m often asked what the solution is to this problem. While technology can provide one component of a full-spectrum solution to defeat contraband cell phone flows and usage, it is a multifaceted problem that requires a multipronged approach — detection, defeat, deterrence, operations and evidence recovery.
We should also remember the simplest, and frequently productive, approach we can take is to get back to the basics of operational processes and protocols. The sad reality is that the problem is one largely manufactured by corrupt staff.
Strengthening entrance procedures, banning cell phones for all staff regardless of position; improving searches; promoting legislation criminalizing cell phone possession and strengthening the investigatory process and consequences will certainly go a long way toward deterrence.
Without government-funded testing of jamming technology and reductions in the cost of detection, both solutions are likely to remain on the margins of the main. Although some in corrections have taken on the challenge, moving forward, it is imperative that corrections decision makers, organizations and lawmakers at every level make the problem of contraband cell phones a priority. The problem is not going to go away of its own accord.
Alex Fox is recently retired from his position as director of security technology with the Massachusetts Department of Correction following 29 years with the agency. He now serves as a consultant for the corrections industry.