Can Your Cell Phone Be Used Against You?

In criminal, civil and family law matters, attorneys for the government and for their respective clients are using cell phone technology to track the movement of individuals.  Some courts have allowed lay individuals such as police officers and detectives to testify giving opinions as to where a cell phone was on any given date and time.  The assumption is that where the cell phone was, so was the owner of the phone.  Other courts have allowed only persons qualified in the cell phone industry or having special training and experience to give expert testimony.

The Federal Communications Commission mandated that wireless carriers provide Emergency 911 location information by one of two methods, handset based or network based.  Handset based technology is where location information is generated by GPS or similar technology installed in the caller’s handset.  Network based technology is where the location information is generated by analyzing the caller’s wireless signal in relation to nearby cell sites in the carrier’s network.   The FCC’s rules require wireless carriers to identify the caller’s location for a specified percentage of 911 calls within a range of 50 to 150 meters for handset-based GPS technology and 100 to 300 meters for carriers that use network-based technology.

The design of a cellular network is divided into “geographic coverage areas called “cells”.  These cells are arranged in a pattern of a hexagonal grid or honeycomb.  The point where three cells meet is called the cell site or cell tower.  The size of each cell’s coverage area is determined by the number of antennas operating on the cell site, the height of the antennas, the topography of the surrounding land, and obstructions that may be present.   As long as a cell phone is turned on, it periodically transmits a signal to the network.  A cell phone connects to the cell site with the strongest signal, not to the closest signal.  The physical characteristics of the phone itself may affect the signal strength.  Such factors as the wattage output and the generation of the phone’s broadband capability, may affect signal strength.

Individuals who have been qualified as an expert, have made inaccurate assumptions leading to unreliable evidence, without considering some of the factors stated above.  Some of those false assumptions are picking up pings from one cell tower, whether other cell towers could have picked up the pings due to tower updates or maintenance.  There are at least 20 different factors for an expert to consider in rendering an opinion.  If the expert testifying against you has not considered these factors, the evidence against you may be unreliable which may result in your criminal conviction, or lead to false information in a divorce or custody case or place you at a location creating civil liability to you or your employer.  It is important to authorize your attorney to hire a qualified expert to confirm or dispute evidence based on cell phone ping location technology.