Understanding Cellular Sites

Cell sites, often called cell towers, are commonly used by law enforcement to put defendants in a specific area. This can be extremely helpful or detrimental; regardless the site information is subject to interpretation. Above and beyond the immediate implications, the cell site information has hidden factors. Cell sites are divided into sectors and simply being near a cell site/ tower is not as important as the designation of the sector (or side) of the site. And even then, the direction or “Azimuth” of the sector, signal strength, and call traffic of the site becomes relevant. Again, this information is not always presented by law enforcement, making it imperative you have someone who understands and can obtain this information.
I have seen too often, law enforcement convinces a Grand Jury there is evidence of cell towers putting the defendant simply in the location of a crime. This reference, alone, has caused people to be indicted.
The truth of the matter is a cell sites can have a range as far as 20 miles and as close as 0.1 mile. More importantly, cell sites register limited information and are not there for the purposes of law enforcement, rather to connect your phone call to the person whom you dialed. The phone company keeps records for their needs, not for the needs of law enforcement. In fact, in 2010, a law was passed that cell phones have to be equipped with GPS (Global Positioning System). Those records, however, are maintained for a limited period of time and are significantly more accurate than cell site depiction.
If the police do not seek the information and that information is no longer available, who becomes accountable? The defendant. Many years ago, I worked on a quadruple homicide, death penalty case. The police investigated two brothers, one who lived in the vicinity of the crime and the other lived sixty miles away. They served a search warrant on the brother in the area, believing they could not go wrong because the odds were he’d be near his home. The other brother’s records were not searched. Neither was arrested for 58 days from the murder with the detectives fully aware that cell site records were maintained, by their respective carries, for only 55 days. After the two were charged, it was impossible to obtain the records for the one 60 miles away. Never believe law enforcement won’t manipulate information.
Recently, I was called upon to testify in a two count home invasion case. Prior to the trial, the Prosecution produced a 3D video prepared by LA Clear, a division of the California Department of Justice, whose sole purpose is to interpret cell records. The way the video was designed was so exacting, it appeared to have been prepared with the use of GPS coordinates. Under the discovery disclosure laws, Brady vs. Maryland, I requested the information used to produce this 3D video interpretation of cell sites/ towers. Forced to admit the video was an interpretation, the Prosecution withdrew the video before the Court could rule to exclude it. The defendant was acquitted on one of the counts and hung, in favor of acquittal, on the second.
The worst part of this story, the co-defendant took a plea deal because his “expert” supported the video. Scary. And shows the importance that you find and work with the right people.