Analysis of Mobile Phone Geolocation Methods Used in US Courts

Call Detail Records (CDR) are files that collect information about every call made on every cellular wireless network in the USA. Network operators capture and archive these files in the regular course of daily operations for internal use by their technical departments, but CDR files are also used as evidence in criminal cases to estimate the locations of mobile phones and infer the locations of individuals. Courts are tasked with determining the admissibility of evidence and are sometimes presented with CDR interpretations that are not based on legitimate radio-frequency (RF) engineering science. This paper discusses CDR-based geolocation methods that are well founded in the science of RF engineering as well as methods that have no basis in RF theory nor any engineering practices.