*This post originally appeared on Patheos.com on October 24, 2014
Cell tower L689, aka the “Leakin Park tower”. Credit to Redditor Anjin who says the radius goes up to 20 miles.
“On May 28th, Lisa Marie Roberts, of Portland, Oregon, was released from prison after serving nine and a half years for a murder she didn’t commit. A key piece of overturned evidence was cell-phone records that allegedly put her at the scene.” This comes from this story featured in the New Yorker earlier this year.
This piece and others describes how the cell phone technology, pre-GPS, is in fact “junk science”. It is nearly impossible to pinpoint a cell phone’s location using the tower that it “pings”. According to the New Yorker article, “(R)ather than pinpoint a suspect’s whereabouts, cell-tower records can put someone within an area of several hundred square miles or, in a congested urban area, several square miles.”
In this well-cited study, published in the Richmond Journal of Law and Technology, the researcher concludes the following:
“Cell site data can track the location of cellular phones if enough information is available to perform triangulation. However, the
accuracy of triangulation depends on multiple factors, from the duration of the call to the geography of the region. The interpretation of historical cell site data can prove a useful investigative tool, if law enforcement properly recognizes its limits. From such information, law enforcement can determine the general coverage area from which a phone call was placed, but not the precise location within that area. Historical cell site data can also show that a call was not made from a certain area.”
Not only do experts debunk the idea that a cell phone’s location can be determined from assuming the tower it “pings” is closest to it, courts have actually excluded cell tower evidence, finding it unreliable as to the location of the phone at the call. Across the country, cell phone evidence based on mapping the towers being hit is now under legal attack and scrutiny: Continue reading