Is It Legal to Hire a Private Investigator to Follow Someone?
If you suspect a cheating spouse, need to locate a missing person, or have concerns about someone's activities, you may be wondering: is it actually legal to hire a private investigator to follow someone? The short answer is yes — in most circumstances, hiring a licensed PI to conduct surveillance is perfectly legal. But the longer answer involves important boundaries that both you and the investigator must respect. Understanding those limits before you hire anyone could save you from serious legal trouble.
What Legal Surveillance Actually Looks Like
Licensed private investigators are trained to observe and document what happens in public spaces. When a person is out in the world — driving on public roads, walking into a restaurant, meeting someone at a park — they generally have no reasonable expectation of privacy in those moments. A PI can legally watch, photograph, and video record activities that are visible from a public vantage point.
Common legal surveillance activities include:
- Following a subject on public roads and in public places
- Photographing or filming someone in plain public view
- Documenting who a person meets with or where they travel
- Observing and recording activities visible from a public street or sidewalk
- Compiling a timeline of a subject's movements based on public observation
The key principle is reasonable expectation of privacy. Once someone steps into a private space — their home, a hotel room, a private office — the rules change significantly, and a legitimate investigator will know where that line is.
What a PI Cannot Legally Do
This is where many people are surprised. Hiring a licensed investigator does not give either of you a license to break the law. A reputable PI will refuse requests that cross legal boundaries, and a client who pressures an investigator to do so could themselves face legal consequences. Illegal activities include:
- Trespassing — entering private property without permission to conduct surveillance
- Wiretapping or recording private conversations — federal law and most state laws strictly prohibit intercepting private communications without consent. You can review the basics of federal wiretapping law at Law Cornell's legal reference library.
- Installing GPS trackers without authorization — in many states, placing a GPS device on a vehicle you do not own is illegal, even if the subject is a spouse. Laws vary significantly by state.
- Impersonating law enforcement — a PI has no police powers and cannot represent themselves as a government official
- Accessing protected records illegally — financial records, medical records, and certain personal data are protected by law and cannot be obtained through deception or hacking
- Harassment or stalking — surveillance that crosses into repeated, threatening contact is illegal regardless of who conducts it
If an investigator offers to do any of the above, that is a serious red flag. Walk away.
How Licensing Laws Affect What's Permitted
Private investigator licensing and the scope of permitted activities vary from state to state. Some states have strict licensing requirements, mandatory training hours, and clear statutory definitions of what PIs may do. Others have lighter frameworks. Texas, for example, requires PIs to be licensed through the state's Department of Public Safety and has specific rules governing surveillance, record access, and conduct.
Before hiring anyone, you can verify an investigator's license through your state's licensing authority. A good starting point is USA.gov, which provides links to state government agencies where you can look up professional license holders.
Your Reason for Hiring Matters — Legally and Practically
The purpose behind the surveillance matters more than many people realize. Courts and law enforcement look at intent. Common legitimate reasons people hire PIs for surveillance include:
- Suspected infidelity in a marriage or domestic partnership
- Child custody disputes where a parent believes the other is not providing a safe environment
- Insurance fraud investigations (often hired by businesses or attorneys)
- Locating a missing adult family member
- Verifying that an employee is honestly reporting an injury or absence
However, hiring a PI to harass an ex-partner, intimidate someone, or gather information for an illegal purpose is not protected and could expose you to civil or criminal liability. If your situation involves legal proceedings — divorce, custody, litigation — consult a licensed attorney before hiring an investigator. An attorney can help ensure that any evidence gathered is collected in a way that may actually be usable in court. You can find general guidance on how evidence rules work through resources like Nolo's legal information library.
Questions to Ask Before You Hire a PI
A professional investigator should be transparent about their methods, licensing, and limitations. Before signing any agreement, ask:
- Are you licensed in this state, and can you provide your license number?
- What specific surveillance methods will you use?
- How do you handle situations where following someone would require entering private property?
- Will any recordings or reports be obtained in a legally admissible way?
- What is your fee structure, and will you provide a written contract?
- Have you done this type of case before?
- What happens if you cannot gather useful information — what am I charged?
A trustworthy PI will answer these questions clearly and will never guarantee a specific outcome. Investigators gather information — they cannot promise what they will or won't find.
Protecting Your Own Privacy in the Process
When you hire a PI, you will typically share information about yourself, the subject, and your situation. Be mindful of what you hand over. Make sure the investigator has a clear privacy policy regarding how your information is handled. The Federal Trade Commission publishes consumer guidance on privacy and background screening that is worth reviewing if you have questions about how personal information may be used.
The Bottom Line
Hiring a licensed private investigator to follow someone is legal when it is done for a legitimate purpose, conducted in public spaces, and carried out by a properly licensed professional who stays within the law. The legality hinges on where the surveillance takes place, how it is conducted, and why it is being done. When the matter has legal consequences — especially in family law or litigation — always loop in a licensed attorney to guide the process.
If you are ready to explore your options, Find A Local PI can connect you with a licensed private investigator in your area at no charge and with no obligation. Simply use our connection form to describe your situation and get started.