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Best Private
Investigators in

Why These Private Investigators?

Our goal is to connect people with the best local experts. We scored private investigators on more than 25 variables across five categories, and analyzed the results to give you a hand-picked list of the best private investigators in Chicago, IL.

Reviewed Curated Top Picks 692 421 15

Our Selection Criteria:

  • 1. Reputation

    A history of delighted customers and outstanding service.

  • 2. Credibility

    Building customer confidence with licensing, accreditations, and awards.

  • 3. Experience

    Masters of their craft, based on years of practical experience and education.

  • 4. Availability

    Consistently approachable and responsive, so customers never feel ignored.

  • 5. Professionalism

    Providing service with honesty, reliability, and respect.

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1Source Private Investigations

1Source Private Investigations is a private investigative agency in Crown Point that was founded in 1999 and has experience in many areas of private investigations with emphasis on legal investigations. The agency carries a $1,000,000 in business liability insurance for errors and omissions coverage even though the regulation only requires $100,000. The agency has “2,000 plus hours of courtroom experience”.

Crown Point, IN 46307


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Arkus is a Northbrook private investigations firm founded in 1975. The firm’s team of experienced investigators provide services such as surveillance, threat assessment, cheating and infidelity proof, undercover work, legal, business, fraud, insurance investigations, process server, and much more. The firm’s investigators are available 24 hours a day, seven days a week. The investigative firm only hires local private investigators with a minimum of 5 years of experience in the field. The firm also belongs to the National Council of Investigative and Security Services, and the Associated Detectives and Security Agencies of Illinois.

Northbrook, IL 60062


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Arnold M. Diamond

Arnold M. Diamond is a licensed private detective agency in Lincolnwood that was founded in 1970. The agency’s services include background checks, trademarks, malpractice, patent investigations, asset searches, employee integrity checks, undercover surveillance, and other investigative services. The investigative agency offers a no obligation and confidential free initial consultation at their office or the prospective client’s preferred location.

Lincolnwood, IL 60634


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Heritage Investigations and Surveillance

Heritage Investigations and Surveillance is a licensed private investigative agency in Chicago with over 33 years experience in the area. The agents are licensed by the state of Illinois and are specially trained to conduct investigations and surveillance regarding marital infidelity and child custody. Other services of the agency are alimony termination, fraud investigations, surveillance services, and GPS tracking in the case of cheating spouses.

Chicago, IL 60602


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Illinois Investigative Solutions

Illinois Investigative Solutions is a client oriented private investigative agency in Naperville offering a range of services including matrimonial cases, due diligence, criminal, civil, workers compensation, and attorney support. Other services provided by the agency include locating missing persons and technical surveillance counter measures. The owner and chief investigator of the agency was an investigator with the United States Army Criminal Investigation Division Drug Suppression Team, where he was awarded the Army Achievement Medal for his contributions.

Naperville, IL 60540


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Lawrence Ryan Investigation

Lawrence Ryan Investigation is a private investigative agency in Oak Lawn whose “strength is field work.“ The agency’s services include attorney litigation and process support, corporate investigation and risk management, and domestic investigations. The agency brings over 38 years of law enforcement and investigations experience. A client says of the private investigative agency, “I confidently recommend Lawrence Ryan Investigations, Inc. because all my expectations were exceeded.”

Oak Lawn, IL 60453


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Michael P. Slevnik Private Detective

Michael P. Slevnik Private Detective in Chicago offers criminal defence investigations, missing persons investigations, firearms training, NRA basic pistol courses, covert surveillance, background investigations, and much more. Michael Slevnik is a Certified Illinois Concealed Carry Instructor, an NRA Certified Pistol Instructor, an NRA Certified Rifle Instructor, an NRA Certified Shotgun Instructor, an NRA Personal Protection Inside the Home Instructor, and an NRA Personal Protection Outside the Home Instructor. Mr. Slevnik is also a member of the International Law Enforcement Educators and the Trainers Association.

Hickory Hills, IL 60462


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Mid-West Protective Service

Mid-West Protective Service offers an array of protective, investigative and security services in Chicago and opened in 1993. The agency’s services include private investigations, surveillance, polygraph and lie detector exams, bodyguard services, security, eavesdropping, countermeasures, and security consulting. The agency’s president has over 30 years experience in law enforcement, private investigations, and security. The firm is a member of the American Polygraph Association, the Law Enforcement Alliance of America, the National Association of Investigative Specialists, and the National Association of Legal Investigators.

Chicago, IL 60641


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MSI Investigative Services

MSI Investigative Services is a private investigative agency in Chicago that has been serving private individuals, attorneys, government, and businesses for over 50 years. The agency’s services include lie detection, cell phone forensics and cellular data recovery, debugging and bug sweeps, computer forensic data recovery, cheating partner, missing persons, surveillance and much more. The agency has an A+, Complaint-free, Accredited Better Business Bureau rating as a testament of high-quality business practices.

Chicago, IL 60647


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Northshore Process Service Network

Northshore Process Service Network in Chicago, Illinois, is a private investigation firm offering its services to residents and business owners throughout the greater Chicago area. Doing business for more than a quarter-century, the firm offers an array of services, including workplace and theft investigations, surveillance, process service, pre-marital and pre-employment searches and screenings, and judgment recovery. It also takes on insurance claims investigations, juror screenings, activity checks, adultery/cheating investigations, and asset searches.

70 West Madison St
Chicago, IL 60602


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ONQ Protection and Investigation Services

ONQ Protection and Investigation Services is a private investigative agency in Chicago, founded in 2011 by a former Homeland Security ICE-Investigator with over 10 years experience. The agency’s areas of expertise include child custody, background investigation, witness statement, undercover assignment, electronic debugging, and much more. The agency also offers training courses for concealed carry weapons, firearm training, and a permanent employee registration card security officer course. The agency is a member of NCiSS, NISP, and WAD.

Chicago, IL 60618


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Robert G. Hanrahan Investigations

Robert G. Hanrahan Investigations is a licensed private investigation firm in Chicago providing complex intelligence gathering services to law firms and businesses as well as private individuals since 1956. The firm’s services include matters such as personal injury, product liability, environmental issues, criminal activity, and trademark infringement, with a major focus on private investigations involving plaintiffs, personal injury attorneys, and asbestos litigation. The firm has over hundred trials to its credit and has assisted attorneys with over $1 billion dollars in settlements or verdicts. In addition, the firm has also photographed and videotaped hundreds of accidents.

Chicago, IL 60611


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RWS Private Investigations

RWS Private Investigations is a family-owned private investigative agency that has been performing private Investigations in Chicago since 1997. The founder enjoyed a 29-year career with the Schaumburg, Illinois Police Department and received many awards including the "Director's Award" from the FBI, the Medal of Honor from the Cook County Sheriff, and the Cook County State Attorney's Award for Investigative Excellence.

Chicago, IL 60602


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Subrosa Investigations

Subrosa Investigations is a private investigative agency in Glenview offering litigation support to attorneys and insurance companies, enhanced background checks for private equity, fund of funds, hedge funds and institutional investors, pre-employment background checks for multi-national corporations, and intellectual property and trademark enforcement for the retail sector. The agency is a member of the National Council of Investigation and Security Services, the Arizona Association of Licensed Private Investigation and the Special Agents Association.

Glenview, IL 60025


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VTS Investigations

VTS Investigations is a premier Chicago private detective, security and process serving agency founded in 1979. The firm has extensive experience dealing with investigative issues such as asset searches, computer forensics, eavesdropping sweeps, litigation support, fraud and theft investigations, and surveillance. The firm is fully insured and licensed for investigative duties in the area. The investigative agency is affiliated with different associations including the World Association of Detectives, the National Association of Legal Investigators, the Associated Detectives of Illinois, and the National Council of Investigation.

Chicago, IL 60611


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