U.S. Department of Justice
Office of Justice Programs
National Institute of Justice

IN
short

T oward C riminal J usTiCe s oluTions

DEC. 09
NCJ 227539

Cell Phones Behind Bars
A widespread technology that allows people to
connect with anyone, anywhere, has created
concerns for corrections officials. The use of inexpensive, disposable cell phones has changed
the age-old cat-and-mouse game of controlling
whom inmates communicate with in the outside
world and is creating serious problems for public
safety officials.
In the 1990s, cellular phones were larger and
heavier and had audio capabilities only. Today
they are lightweight, can be thinner than a matchbook, and can send both audio and data, including
written messages and streaming video. Although
these advances are welcome in society in general, they have had a negative impact on the law
enforcement community, as criminals have taken
advantage of cellular technology to conduct illegal
activities.

A WidespreAd problem
The issue of cellular phone use by criminals,
especially prison and jail inmates, gained national
attention when a death row inmate used a cell
phone to threaten a Texas senator. In Nevada,
prison officials fired a dental assistant for helping
an inmate get a cell phone to plan a successful
escape. In New York, an inmate used a cell phone
to orchestrate an attempted escape while on a
medical transfer. In Tennessee, prison officials
banned jars of peanut butter after learning that an
inmate accused in the shooting death of a guard
had used a jar to hide the cell phone he used to
coordinate his escape. Prisoners have also used
cell phones to harass and threaten their victims. In
Texas, courts have convicted more than a dozen

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corrections officers in recent years for accepting
bribes in exchange for cell phones or phone parts.

ContrAbAnd
The number of contraband cell phones being
confiscated is also noteworthy. For example, in
California, correctional officers seized 1,331 cell
phones in the first six months of 2008. Corrections
officials in other states have also reported finding
hundreds of cell phones.
Corrections officials have spent millions of dollars
to outfit prisons and jails with metal detectors,
but the detectors do little to stem the flow of cell
phones from the outside. Some cell phone parts
are made of plastic and go undetected.

shutting doWn Cell phones
Blocking cell phone service involves using technologies to stop the transmission or reception
of other radio signals. In some cases, blocking
signals can be tuned to leave specific frequencies open, which would allow for communication
among corrections personnel, or they can block
almost all signals. The power of the blocking
signal determines how large an area is affected.
The area could be as small as a cell block or large
enough to cover an entire prison. Blocking systems can cost as little as $1,000, but more powerful systems can cost tens of thousands of dollars.
Another technology allows for spoofing cell
phone signals. Spoofing involves intercepting
selected cell phone transmissions and preventing them from reaching the intended recipient.
Spoofing uses sophisticated software and is

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www.ojp.usdoj.gov

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possible without the active participation of the cell
phone network providers. A drawback to selective
blocking and spoofing is the potential for inmates
to use approved cell phones that belong to staff
members.

FederAl government rules
The Communications Act of 1934 and the
Telecommunications Act of 1996 prohibit the
operation of cell-phone-jamming equipment by
any person, including state and local officials.
Specifically, Section 333 of the Communications
Act prohibits willful or malicious interference with
any licensed or authorized radio communications
equipment or with radio equipment operated by
the United States government. In addition, the Act
prohibits the manufacture, importation, marketing,
sale or operation of devices deliberately designed
to jam or disrupt wireless communications.
Legislation in Congress titled the Safe Prisons
Communications Act of 2009 would let prisons
and jails use cell-phone-jamming technology.

Countering the problem
As they await legislative relief from the problem,
corrections officials are using various technologies that detect and find cell phones. Both

high-technology and low-technology approaches
are being tested and used. Several agencies
have installed sensors that detect and find cell
phones when in use. One such device tested in a
Pennsylvania prison signaled cell phone location
to within four cells on two tiers. Some sensors
can even detect cell phones that are turned off,
but they only work when in close proximity to a
phone, cost between $15,000 and $20,000, and
require trained staff. Others use new detectors
that can identify nonmetallic objects to conduct
searches. For smaller facilities, the use of specially
formulated paints and coatings that block radio
frequency signals may help.
Some correctional institutions use specially trained
dogs to sniff out hidden cell phones. These efforts
have not been rigorously evaluated. Dog training
can cost tens of thousands of dollars. Dogs must
be close to the phone, and anecdotal evidence suggests that the phone must be left in the same place
for a considerable time to be found.
Most of these solutions are expensive and labor
intensive. Each would benefit from a thorough
evaluation.
For more information about NIJ’s Communications
Technology program, see http://www.ojp.usdoj.gov/
nij/topics/technology/communication/welcome.htm.

*NCJ~227539*


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