Browse the Top Private Investigators Serving Glendora, CA

Observant Security/Investigation Services established 1981 providing full field services to it's customers throught the State of California, Nationwide and around the World. When the successful resolution and closure of your most sensitive case relies on information; YOU deserve and MUST therefore DEMAND the BEST. Our dedication to ongoing education and training along with the use of the state of art technology, ensures that we get the job done right and in timely manner.

Since 1967, our main goal is to supply our clients with all the information they need to make the correct decisions about critical issues. We provide discreet private investigation services in Los Angeles, Beverly Hills, San Diego, San Francisco, Houston, Denver, New York City, Washington DC and Virginia, USA and the World. Do you suspect your spouse, partner, business associate or employees is being dishonest? We investigate cases regarding; Criminal, Civil, Personal, Business or missing persons as well as extensive backgrounds and Due Diligence. Est. 1967. Call or email us now, ASAP.

Silent Warrior Investigations provides professional private investigation and lie detection services in Orange, California. With over 30 years of law enforcement experience, we offer criminal investigations, civil litigation support, covert surveillance, executive protection, and polygraph exams. Our team delivers reliable, confidential results to attorneys, businesses, and individuals across Southern California and nationwide.

Los Angeles Process Server provides professional legal document delivery services throughout Los Angeles County and California. Our core services include process serving with unlimited attempts, court filings, and investigative services. We specialize in delivering summons, subpoenas, restraining orders, and eviction notices with guaranteed compliance and timely execution.

Empire Pacific Investigative Services delivers expert private investigation services across Los Angeles Metro, specializing in infidelity cases, asset research, background checks, and corporate investigations. Founded by seasoned federal agents, we combine decades of law enforcement experience with cutting-edge technology to uncover critical information. Our client-centric approach prioritizes discretion, reliability, and actionable intelligence to meet legal, personal, or business needs.

The Centurion Group provides comprehensive security and investigative services, combining law enforcement expertise with cutting-edge technology. We specialize in physical security, executive protection, and electronic systems integration for clients ranging from corporations to high-profile individuals. Our 24/7 operations and 99% client retention rate reflect our commitment to excellence.

Starside Security & Investigation provides comprehensive security, detention transport, and investigative services to government agencies, corporations, and high-profile clients nationwide. With over 25 years of experience, we specialize in physical security, executive protection, and forensic investigations, combining veteran expertise with advanced technology. Our 24/7 operations and nationwide presence ensure reliable, customized solutions for diverse security needs.

RCS Investigations provides professional investigative services including police/fire background checks, surveillance, and internal affairs investigations. Our team of retired law enforcement professionals ensures compliance with state and federal regulations while delivering detailed, confidential reports. We serve public agencies and private clients across Southern California with a focus on accuracy and ethical standards.

Parrent Smith Investigations provides expert private investigation services including asset location, background checks, and litigation support. Specializing in complex cases, we assist clients in uncovering critical information for legal, corporate, and personal decision-making. Our team combines decades of experience with ethical practices to deliver reliable, actionable insights.

Encinas Investigations-PI delivers certified firearms training, tactical courses, and security officer programs in Anaheim Hills, CA. With over 40 years of experience, we offer state-approved CCW certification, patrol rifle instruction, and bilingual training in English and Spanish. Our accredited curriculum prepares students for careers in private security and public safety through hands-on instruction from active industry professionals.