Abstract
Mobile phones are increasingly a source of evidence in criminal investigations. The
evidence on a phone is volatile and can easily be overwritten or deleted. There are many
tools that claim to radio isolate a phone in order to preserve evidence. Unfortunately the
wireless preservation devices do not always successfully prevent network communication
as promised. The purpose of this study was to identify situations where the devices used
to protect evidence on mobile phones can fail. There has been little published research
on how well these devices work in the field despite the escalating importance of mobile
phone forensics. These shielding devices were tested using mobile phones from three of
the largest services providers in the U.S. Calls were made to contact the isolated phones
using voice, SMS, and MMS at varying distances from the provider’s towers. In the
majority of the test cases the phones were not isolated from their networks despite being
enclosed in a shielding device. It was found that SMS calls penetrated the shields the
most often. Voice calls were the next most likely to penetrate the shields and MMS were
the least.
