From minor crimes to major cases, law enforcement is faced with the proper handling and analysis of these devices.

You see them everywhere, cellular phones and handheld devices (smart phone, BlackBerry, iPhone, etc.). They are a part of our world’s culture. Dr. Thomas P.M. Barnett, author of Great Powers: America and the World After Bush, remarked in a recent radio interview, “…cell phones are selling like crazy in rural India…farmers are buying them before they put a toilet in their house…” Additionally, recent news reports indicate that, statistically, 90% of all Americans own a cellular phone. Having this kind of societal importance and wide distribution, it is not surprising that cellular phones and handheld devices are being widely used in even the most minor criminal activity. These devices can provide significant evidence in major cases. This article will discuss considerations for law enforcement in the handling and analysis of these devices.

Not so long ago, a cellular phone had a rudimentary call history, phone book, and messaging system containing both text and voice messages. Now these handheld devices can be as complex as small computers. Even the least complex model can contain sophisticated multimedia messaging, Internet access, integrated global positioning system (GPS) functions, data connectivity, etc. These functions can provide a wealth of information to law enforcement.

Cellular phones operate on radio frequency (RF) protocols. When a cellular phone is turned on, it searches for the strongest signal, usually from the nearest cellular tower, or the one having the best line of sight. As the device is transported, it will continue searching and adjusting to utilize the tower with the strongest signal. The designation of the most recently connected tower is recorded as a database entry in the cellular phone file system. Moving to a new area will cause this entry to be updated. With an active connection to the system, service providers can utilize low call volume periods to update phone connection (roaming) and file system software. These updates can have an impact on the stored data on a device.

Some individuals use a pass code lock to secure their phone. When the phone is turned off, or loses battery power, the lock will be in place when the phone is powered on again. This situation can frustrate the examination of the phone. While this is a concern, instances of locked phones are a low percentage of handheld devices examined. In some of these incidents, the pass code can be obtained through examination software.

On or Off?
Like all forms of evidence, handheld devices require certain precautions to preserve their value for an investigation. During the collection of cellular phones, there has been a debate on how to best preserve their data. This debate centers on whether to turn the phone off or leave it on at collection. It is recommended to power the phone off to preserve data and battery power. If for some reason this is not possible, then the phone needs to be protected from cell tower signals. There are packaging products created for signal protection, such as the Stronghold Bag™ (Paraben Corporation), or an unlined quart-sized paint can, also known as an arson can. However, leaving a cellular phone powered on in a signal blocking container increases the device’s active search for a cellular network. This increased activity will cause battery failure at a quicker than normal pace. If protective packaging is utilized, then a method of powering the device should be considered, or the examiner should be alerted so that an immediate examination can be conducted.