In both California and Texas, the purchase of prepaid cellular telephones by suspicious person has been reported to local and federal authorities. On December 31, 2005, store employees in Hemet, California reported the purchase of 150 prepaid telephones to local and federal authorities. Early that month, in Midland, Texas, store employees reported that six suspicious individuals attempted to purchase 60 telephones.
A copy of the incident report (unconfirmed) prepared by the Midland Police Department is available here.
According to ABC new, federal authorities have begun an investigation into the purchase of large quantities of pre-paid or disposable cellular telephones. Retail and online outlets offer sales and activation of pre-paid cellular telephones which do not require a contract or credit check. The ready access and anonymity offered by these devices make them attractive to criminals and perhaps even terrorists.
As a means of communication pre-paid telephones offer several tactical advantages. First, they provide high-tech, virtually untraceable, communications gear. Because they do not require a contract or credit check, almost anyone can purchase one, under almost any name. Tracing back a number to an individual may well become virtually impossible. Furthermore, the low price provides the additional tactical advantage of secure communications because criminals and/or terrorists can change devices and numbers thereby avoiding traditional wiring taps.
An additional threat to American security may be the use of cellular telephones as a means to remotely detonate explosives. Remote detonation gives terrorists other tactical advantages. Remote detonation can occur by either re-wiring the cellular telephone so that when it is called instead of ringing the electrical current is used for detonation. Also, the alarm clock we typically use to remind us of the time can be used as the timing device for the detonation.
Remote detonation is used to time events, allow for a target to pass near a pre-positioned device, allow a device to be moved into position, or provide a delay in activation for escape. It is suspected that cellular telephones were used as a means of remote detonation in both the Madrid and London bombings. Remote detonation does not necessarily preclude a suicide bomber. By remote, it is meant that the time of detonation is pre-determined. It may well be that the London bombers were so well synchronized because the explosions were remotely timed by pre-setting a cellular alarm clock.
Law enforcement officials use a number of devices to investigate and counter the tactical advantage. For instance, Triggerfish is a relatively old-style technology that can home in on a cellular telephone when they are in use. However, this still requires that law enforcement know the cellular telephone number they are trying to track. Again, this highlights the difficulty in pursuing investigative leads on disposable cellular telephones. Additionally, there is technology available and in use which creates a limited cellular telephone dead zone. This technology might be useful in creating a “dead zone” under certain circumstances. As an example, a dead zone can be created by jamming the cellular frequencies after one attack in order to prevent secondary devices. Unfortunately, jamming on interrupts all incoming and outgoing calls – it doesn’t discriminate between terrorists and first responders; and, jamming does not effect timing devices.
As it develops this information will be updated at Criminal Justice Online in the open source intelligence section of the forum.