Business Details
30 Years
experience
Emergency
services
Premier Private Investigator Services in Nashville, IL
Founded in 1996 by a retired Illinois State Police Captain with over 41 years of experience, our agency has grown into the premier investigative firm in the Midwest. We strategically deploy licensed professionals with law enforcement backgrounds across key geographic areas to deliver aggressive yet ethical results. Our team of 27 investigators collectively brings over 100 years of industry expertise, supported by advanced technology and specialized resources. We maintain strict confidentiality while providing comprehensive services including surveillance, background checks, fraud investigations, and executive protection. Our security operations are led by a former U.S.Marine Corps member with dual expertise in law enforcement and management. We collaborate with federal and local agencies on intellectual property cases and maintain memberships in elite professional organizations like the National Council of Investigators and the Council of International Investigators. Our fee structure remains competitive and adaptable to case complexity, with free initial consultations available for all clients.
Services
Surveillance
Background Checks
Fraud Investigations
Missing Persons
Criminal Investigations
Intellectual Property
Executive Protection
Child Custody
Workers' Compensation
Process Service
Details
- Year established: 1996
Highlights and features
- Our team has over 100 years of combined investigative experience
- We employ current and retired law enforcement professionals
- We offer 24/7 emergency investigative services
- We maintain memberships in elite professional organizations
- We utilize advanced surveillance technology and techniques
Services
Surveillance Investigations
Our licensed investigators conduct electronic and physical surveillance using advanced technology. We provide discreet monitoring for infidelity cases, corporate investigations, and legal evidence collection. Our team has over 20 years of experience in surveillance operations.
Background Checks
We offer comprehensive background checks for employment, pre-marital, corporate, and tenant screening purposes. Our investigations include criminal history records, financial background checks, and civil records verification across multiple states.
Fraud Investigations
Our certified fraud examiners investigate insurance fraud, embezzlement, and financial misconduct. We use surveillance and forensic accounting techniques to document fraudulent activities and support legal proceedings against perpetrators.
Missing Persons
We conduct missing persons investigations using advanced database resources and field techniques. Our services help locate individuals for legal matters, family reunifications, or reconnection with lost contacts across the Midwest region.
Criminal Investigations
Our former law enforcement team provides criminal investigation support for defense cases. We collaborate with attorneys to gather evidence, interview witnesses, and build defense strategies for clients facing criminal charges.
People
William R. Barrett
Founder
Retired Illinois State Police Captain with 41 years of law enforcement experience. Founded the agency in 1996 and built it into a premier Midwest investigative firm with 27 licensed investigators.
Questions
What services does Advanced Investigative Services offer?
We provide surveillance, background checks, fraud investigations, missing persons cases, criminal investigations, intellectual property protection, and executive security services.
In which states do you operate?
We serve Illinois, Missouri, Arkansas, Indiana, Kansas, Kentucky, and Tennessee with immediate investigative response.
What experience do your investigators have?
Our 27 licensed investigators include current and retired law enforcement officers with over 100 years of combined industry experience.
Do you offer 24/7 emergency services?
Yes, we provide immediate response for urgent investigative needs at any time of day or night.
How are your fees structured?
Our fees are competitive and based on case complexity, with free initial consultations available for all clients.