Joseph Sierra Joins Cornerstone Discovery's Team as Nation's Leading Expert in Cell Site Forensics

​​​Cornerstone Discovery welcomes the ample experience of Joseph M. Sierra as one of the nation’s leading experts in Cell Site Analysis. Sierra will draw on his expertise to provide digital forensic services and expert witness testimony on cases that involve digital information, specifically cell site analysis, mobile phone forensics, and general digital forensic knowledge.

Sierra brings with him over 10 years of experience in cellular technology and digital evidence. He has worked in the legal industry since 2008 and spent the last 10 years at T-Mobile as a Legal Compliance Specialist and Senior Testifier in the Law Enforcement Relations Department. Sierra holds a B.A. in Criminal Justice from Rutgers University and M.S. in Criminology-Intelligence and Forensic Data Analysis from St. Joseph’s University. 

Before joining Cornerstone Discovery, Sierra managed a team of seven expert testifiers and developed relevant policies and procedures to optimize criminal investigative operations. This experience led Sierra to perform numerous expert training sessions in Call Detail Record (CDRs) analysis for internal employees, prosecutor offices, and law enforcement agencies, such as the FBI. At T-Mobile, Sierra responded to and analyzed over 6,000 cellular reports and provided testimony in over 400 trials relating to mobile data, GPS tracking, electronic surveillance (PEN, T-III, FISA), and timing advance. Sierra has also been qualified as an expert witness in local, state, and federal courts across the US in cell tower data analysis, RF engineering, GPS/Triangulation-Cellular, and cellular forensics. Jason Silva, Managing Director of Cornerstone Discovery, said, “We’re very excited to have Joe on board. His depth of experience, knowledge, and analytical capabilities in cellular technology and forensics will complement our growing team of seasoned digital forensic examiners.”

To learn more about Cornerstone Discovery’s Digital Forensic services, visit our website at, or to discuss a case involving Cell Site Analysis, or for CLE and other teaching opportunities, please contact, Joe Sierra at (267) 639-6900 or email,

Cornerstone Discovery, headquartered in Philadelphia, PA, is an award-winning litigation support firm that provides top-rated criminal & civil litigation support and consulting services in digital forensics, e-discovery, litigation, and trial support. Our experienced professionals and certified technical experts have a comprehensive understanding of technology, investigations, and the legal process. Cornerstone Discovery empowers law firms and corporations in and out of the courtroom and ensures every case is built on a solid foundation. For more information on Cornerstone Discovery, visit

For Press Inquiries Contact:

Grady Walters, Director of Marketing

(267) 639-6900

Source: Cornerstone Discovery


Categories: Law

Tags: Cell Phone Forensics, Criminal Law, Digital Forensic Examiner, Digital Forensics, Expert Witness Testimony

About Cornerstone Discovery

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Cornerstone Discovery is a single-source E-Discovery, Digital Forensic, and Litigation Support firm, founded in 2005. We are proud to support clients both locally and nationally with certified technical experts and experienced trial technicians.

Cornerstone Discovery
4775 League Island Blvd
Philadelphia, PA 19112-1220
United States