Texas License: C-11847 | Louisiana License: 7311-011910-LA | Alabama License: 395

Texas License: C-11847 | Louisiana License: 7311-011910-LA | Alabama License: 395


Gillespie Security & Investigations (GSI)

Founded in 2004, Gillespie Security & Investigations (GSI) has one primary objective: to provide comprehensive, confidential and ethical investigative services to attorneys, businesses, organizations, courts and individuals. As a full-service investigative agency, GSI specializes in criminal defense, forensic consultations, background investigations, surveillance, missing persons, crime scene reconstruction, infidelity investigations, personal security and investigation/security training.

Mark Gillespie has over thirty-three years of investigative and forensic science experience with a master's degree in forensic science from George Washington University. A former special agent for the Air Force Office of Special Investigations (AFOSI), Gillespie has commanded many investigative units in the U.S. and overseas. After retirement from the Air Force, Gillespie became the Director of Forensic Science for the Austin (Texas) Police Department where he managed the department’s crime laboratory and forensic science services.

In 2002, Gillespie was responsible for introducing forensic science to SEU which led to the creation of the Forensic Science Undergraduate Degree program. From 2002 to 2008, Gillespie served on the faculty at St. Edward's University (SEU) as an instructor of forensic science, crime scene investigation and criminal investigation.

Gillespie is former president of the Texas Association of Licensed Investigators (TALI) and currently serves as Region Four Director for the National Council of Investigation and Security Services (NCISS) and is licensed in Texas, Alabama and Louisiana.

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605 South Bell Blvd, Suite 104
Cedar Park, TX 78613
(512) 680-5851