Since 1988, John A. DeMarr P.I. has been providing private detective services and private investigation services to businesses in California and beyond, including law firms, insurance companies, major corporations and small business.

Our California-based private investigations and private detective firm also counts many private citizens among our clients. We investigate both online and offline activities. If you have a hunch, we will find the truth, as we have done for so many clients.

Staffed by police-trained, seasoned professional investigators, we're trained to deal with all aspects of private detective work, private investigation, process service and security.

Every member of our firm must pass an extensive criminal background investigation, ensuring us and our clients that all agents bearing our company patch are qualified and reliable.

In our California private detective work we utilize sophisticated investigative techniques, and incorporate the latest technology. This, coupled with our California agency's tried-and-true, street-smart investigative experience, provides our clients with the best possible private detective services. Our staff excels in solving complex and sensitive problems.

No matter what type of investigative work, private investigations, process service you seek, you will find us knowledgeable, skilled and professional.

John A. DeMarr, P.I. is proud to be affiliated with private investigation, private detective, and process serving professional organizations including The California Association of Licensed Investigators, The California Association of Process Servers, and The National Associations of Process Servers, just to name a few.

We have the experience, training, and discretion to design and implement specialized detective services to meet your specific needs. We are pleased that you are considering us for your investigative and security needs, both online and offline. We look forward to working with you.