NELOS – Network Event Location System by AT&T

NELOS – Network Event LOcation System developed by AT&T provides location information for cellular devices within their network.  Law Enforcement has become aware of this data and routinely requests it when obtaining CDRs (Call Detail Records) in search warrants.  Many prosecutors use these records in criminal proceedings without providing any supporting documentation concerning the admissibility of such records .  Prior to any digital evidence being accepted in a criminal preceding it should meet the standards outlined in US v Evans and pass a Daubert hearing (also known as a Shrek hearing in Colorado).  NELOS is a proprietary system with multiple patents and little public information.  Currently, we know of no published independent peer review, publicly released documents from AT&T explaining the system,  or any case where they have released the raw data so it can be verified.   We know of one case in Colorado where AT&T provided an engineer to answer questions in a hearing. When asked how NELOS worked he stated it was proprietary.
The following disclaimer is on every page of the report.
The results provided are AT&T’s best estimate of the location of the target number. Please exercise caution in using these records for investigative purposes as location data is sourced from various databases which may cause location results to be less than exact.
If you are litigating or defending a client where NELOS data is being used and you need an expert in cellular technology, contact RMCF