Hours of Operation: Mon - Fri 8:00am - 8:00pm

"Leadership and Experience that matters."

GRI Investigative Group, Inc., was founded in 2019 by Marc A. Garza with decades of experience in law enforcement and investigations. Based in San Diego, California, we provide comprehensive and reliable investigative services. GRI is committed to delivering meticulous case analysis, uncovering critical evidence, and assisting clients in navigating complex legal challenges with expertise and integrity. GRI is the go-to resource for law firms, corporations and private clients seeking a dependable ally in achieving successful outcomes in court and private sector environments. 


Investigative Expertise:  

  • Criminal Defense Investigations  
  • Civil Litigation Investigations 
  • Family Law Investigations 
  • Background Investigations
  • CA POST Firearms Instructor
  • TSCM Bug Sweeps/Inspections
  • Covert Surveillance Operations 
  • Post-Conviction Investigations

Marc A. Garza

Founder & CEO of GRI Investigative Group, Inc.


Background and Experience:

Marc is a licensed private investigator and CEO of GRI Investigative Group, Inc., a San Diego-based private investigations agency specializing in criminal defense, civil litigation, and high-technology surveillance operations. With over 30 years of law enforcement, investigative, and consulting experience, Marc is a trusted authority in uncovering truth and delivering actionable insights for his clients.


Before founding GRI Investigative Group, he served as a police sergeant, retiring in 2019 after a long career in law enforcement in San Diego, CA. His extensive law enforcement experience included assignments in high-risk patrol, field training (FTO), investigations, Special Weapons & Tactics ("SWAT"), tactical firearms training, and police supervision. He is a respected trainer in the tactical response and mitigation of active shooter events. 


Marc’s comprehensive investigative skills have been utilized by law firms in both state and federal courts, where he has testified in criminal, civil, and family law cases. His expertise extends to felony-level criminal defense cases involving homicides, gang-related violence, and assault with a deadly weapon (ADW). 


As CEO of GRI Investigative Group, Marc leads a team of investigative professionals dedicated to providing meticulous and ethical investigative services. His leadership and strategic vision have positioned the firm as a trusted partner for attorneys, businesses, and individuals seeking thorough and reliable investigative solutions.