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

Expert Legal Investigations, Research and Legal Support Services


"Focused, credible and actionable professional investigations."


"Our objective is to locate actionable evidence for our clients."

GRI INVESTIGATIONS (GRI) is a California licensed private investigation agency that specializes in Civil, Legal and Criminal Defense Investigations.  Our goal is to focus on the needs of our clients by utilizing the latest investigative techniques to gather documentation and evidence. We are experts at gathering information and obtaining evidence for legal cases.  We are committed to keeping well planned and clearly executed investigations. Our team of investigators and research professionals, have developed their experience from law enforcement, private sector and corporate entities. 

Our mission is to provide our clients with actionable evidence and information in a professional, confidential and cost effective manner. Our agency will not take an investigative assignment unless we feel we are suited to deliver precisely what is requested by our clients. 

We utilize fact-finding based investigative methods while performing in the official capacity of a professional investigator for law firms, corporations, public sector entities and private parties. Our success is based on four basic investigative principles:

1) Conduct all investigative tasks in a professional, ethical and moral manner.

2) Conduct investigations within the limits of the law and civil procedures.

3) Remain impartial, unbiased and objective at all times.

4) Maintain confidentiality with clients; protect confidential information.

Our agency is fully insured and licensed by the State of California, Bureau of Security and Investigative Services under License # PI 28059.  Call (888) 519-0555 for a consultation and discussion on how our agency can assist with your case.


We provide services from pre-litigation to trial. We pride ourselves on conducting actionable investigations for the legal community in the following areas:

  • Civil Litigation Support for Attorneys and Legal Professionals
  • Background and Due-Diligence Investigations
  • Witness Locates & Interviews; Statement Documentation
  • Negligence/Personal Injury Investigations
  • Scene Investigations & Evidence Collection
  • Evasive Service of Process


Our domestic investigative services assist our clients in divorce (dissolution), separation, support cases and other family law proceedings in the following areas:

  • Co-Habitation Investigations
  • Child Custody and Activity checks
  • Social Media Investigations
  • Backgrounds/Criminal Checks
  • Process Server/Service of Summons
  • Surveillance Investigations


Our purpose and ethical obligation is to serve in a "checks and balance" role in the criminal justice system. Those accused of crimes have the right to have adequate representation, which may include the need to verify, confirm or dispute evidence used against the accused through an objective investigation. Some of areas where we can assist are: 

  • Discovery document reviews (police reports, evidence and statements.)
  • Witness and Defendant interviews; Statement documentation
  • Locating witnesses through person searches and "Deep Dive" Investigations
  • Scene Investigations & Processing; Photographic & Video Documentation


Our agency can assist all types of organizations in conducting internal workplace investigations. Our goal and objective is to conduct confidential and impartial "Fact-Finding" investigations for the sole use of human resources departments, legal counsel and corporate leadership. 

  • Due-Diligence Investigations
  • Internal Fraud & Employee Theft Investigations
  • Intellectual Property (IP) Theft Investigations
  • Sexual Harassment; EEOC Investigations
  • Threat Assessments within the workplace


"Leadership and Experience that matters......."

Marc A. Garza

Marc A. Garza is the CEO and Qualified Manager of GRI Investigations (GRI) . He is a licensed private investigator and a retired police sergeant with over 20 years of service in San Diego, CA. He specializes in conducting civil, family law and criminal defense investigations for law firms and private clients. He has assisted legal counsel with investigations in numerous civil litigation and felony defense cases in the Superior Court of California, U.S. District Court and U.S. Immigration Court.  He is a member of the California Association of Licensed Investigators (CALI) and the California Defense Investigators Association (DIA). His main goal is to take a collaborative approach to investigations by building long term business relationships with clients and obtaining actionable evidence for their legal cases.  He is licensed by the CA. Bureau of Security and Investigative Services under PI License #28059.


"What clients are saying...."

"We are extremely pleased with Marc and his company's efforts on our case. Their work product is excellent. I would highly recommend Marc for anyone needing his expertise." 

Katharine Tremblay Beck
Tremblay Beck Law

"Mr. Garza is a professional , experienced and efficient private investigator. I have used his services on many of my cases. I highly recommend his services"

Jose Orozco, Attorney-at-Law
Orozco Law Firm, APC

"Whether our office has a civil dispute, divorce case or immigration matter, GRI is the first call we make when we need information that's hard to get."

Ed Perez, Attorney-at-Law
Law Offices of Ed Perez. PLLC

"I always send my clients to GRI. Marc is always very responsive. He has helped many of my clients out. I would highly recommend his (investigative)


Laura Talamantes, Attorney-at-Law
Talamantes Law Firm, APC


For more information about our services and pricing, please fill out the contact form below and your inquiry will be answered promptly. You may also call (888) 519-0555 for further information. 


Division of GRI Consulting Group, CA. BSIS PI License #28059

San Diego Office Location:

Venture Commerce Center

823 Anchorage Place, Suite 100

Chula Vista, CA 91914

P.O. Box 212967

Chula Vista, CA 91921

(888) 519-0555

All Rights Reserved, 2019-2020