Mark Gillespie

Mark Gillespie


Mark Gillespie founded Gillespie Security and Investigations (GSI) in 2004. Although GSI is a full-service agency; one of Mark’s specialties is criminal defense. Following his career as a special agent with the Air Force Office of Special Investigations, he served as the Director of Forensic Science for the Austin Police Department. He initiated and developed a Forensic Science Undergraduate Degree program at St Edwards University. He as an instructor at St. Edwards as well as an instructor at the University of North Texas Professional Development Institute PI Certification Program. A member of the Big 3 Private Investigator Associations, Mark is Region 4 Director for the National Council of Investigation and Security Services. He is active both with Bikers Against Child Abuse and The Valkyrie Initiative which provides transition programs for vets, first responders, and their families.