Drawing on more than a decade of experience, Sean focuses on complex matters involving electronic evidence, including civil and criminal litigation, as well as information security events. Sean is considered a trusted advisor by his clients, and has successfully, and efficiently, identified actionable facts from digital sources in a variety of situations. Sean’s clients appreciate his ability to concisely, and understandably, communicate often technical, complex findings. As it relates to his practice, Sean provides continuity throughout the course of a project, from initial investigation through reporting and testimony.

Sean has been invited by organizations to speak about numerous topics, including smartphone evidence, working with experts, and cyber incidents. Sean has also provided his expertise to national and local news outlets.

Sean earned his bachelor’s degree, with honors, from the University of St. Thomas in Minnesota, and then continued his studies at the University of St. Thomas School of Law. Sean is licensed to practice law in Minnesota state courts. Sean receives ongoing training in digital forensics and incident response from the SANS Institute and is a member of the GIAC (Global Information Assurance Certification) Advisory Board. Sean is also a member of the International Association of Computer Investigative Specialists (IACIS), and InfraGard (an intelligence partnership between the FBI and the private sector).


CFS prides itself on providing the highest quality and unmatched exceptional service deliverables to its clients.


“Thank you for your contribution to the Eleventh Circuit Judicial Conference…your presentation was a smash hit! Without exception, everyone found it fascinating (and a little frightening at the same time!)…..”

Chief Judge, U.S. District Court Northern District of Florida

“…But they did not realize the magnitude of what they had until they asked…..Computer expert Mark Lanterman discovered that spreadsheets from a critical point in the map-drawing process were missing and that software to wipe the files had been used….”

Washington Post (US Supreme Court case on Wisconsin's Gerrymandering)

“Plaintiffs retained the services of Mark Lanterman, a highly qualified computer forensic expert….Mr. Lanterman’s testimony at the permanent injunction hearing was extremely helpful to the Court and critical to the Court’s findings.”

Court of Common Pleas Cuyahoga County, Ohio