Ten Private Investigator Terms to Know

Estimated reading time: 9 minutes

If you’ve ever read a private investigator book or watched a private investigator TV show or movie, you’ve likely heard a number of different terms used by private investigators. Some terms you may have known right off the bat, and others may have left you wondering, “what does that even mean?

Because private investigation has been around for centuries (the first official private detective agency was founded in 1833 by Eugène François Vidocq,) private investigators have adopted a unique terminology specific to the trade. Many of these terms are used in a variety of different industries, however they can take on a new meaning for private investigators.

Whether you’re interested in learning about private investigation or you just want to understand your favorite private investigation movie a little better, you should probably know what certain words mean in private investigation. From skip tracing to surveillance, here’s a list of 10 terms used in private investigation. 

Hidden asset

A hidden asset is an asset that someone attempts to hide from another person or entity. Because assets are technically things of value, there are a variety of different circumstances in which people have an incentive to hide assets. Someone may hide assets in family law investigations, like divorce cases, in order to get a more favorable settlement than their spouse. Someone may also hide an asset when filing for bankruptcy or dealing with collections in order to avoid having to give over certain items to creditors and collectors. A business may also hide assets to undervalue their company, allowing them to pay out less in personal injury or civil litigation cases

People can hide assets in a variety of ways, from not reporting an asset in a financial filing to hiding a physical asset, like a vehicle, in a secret location. Because people can go to extensive lengths to hide their assets, private investigators are often brought in to help uncover them.

PIs may find hidden assets by physically uncovering the location of an asset, however this isn’t as common. More frequently, private investigators perform an asset check online in a private investigator database to uncover any public records that reveal assets so they can bring those records in as evidence. 

Skip tracing

You may have heard the term skip tracing using a number of different ways, but what is skip tracing and how does it relate to private investigation? Skip tracing, or batch skip tracing, is the act of locating a difficult-to-find individual or individuals — and a private investigator is often an expert skiptracer. Private investigators may use skip tracing to locate someone that’s a witness, an estranged family member, or a debtor.

When private investigators skip trace individuals, these individuals are often covering their tracks to avoid being found — meaning they’re moving around or living with a family member or friend. Private investigators can use skip tracing tools in a public and private records database, like a utility record search or a person search by address, to find the address of an individual. If they need to dive a little deeper, private investigators may contact relatives, friends, or business associates of an individual to gain some insight into their whereabouts.


One of the most commonly used private investigator tactics is surveillance. Simply put, surveillance is the act of closely observing a place, person, or thing, in other words, “surveying” it. A private investigator may conduct surveillance on a location to determine if anything shady is going on at the location, like a criminal network meeting. A private investigator may also use video surveillance to help gather evidence for a cold case investigation, or conduct surveillance on a person as part of an insurance fraud investigation process to determine if that person was actually injured.

While physical surveillance, meaning physically observing something, is a common type of surveillance in private investigations, it is not the only kind. Other types of surveillance include:

  • Technical surveillance, which is the process of taking photographs and videos to uncover evidence.
  • Electronic surveillance, another common type of surveillance, can involve wiretapping or using electronic devices like a radio, television, or phone, to observe someone. 
  • Interviews, which are considered a type of surveillance and are often used by private investigators to gather stories from people who may have information about a person.
  • Auto surveillance, which is a specific type of physical surveillance that involves following a person around in a vehicle.
  • Digital surveillance, the observation of someone’s online presence, is becoming more popular as people share greater amounts of information and communication more frequently over the internet. Private investigators can conduct digital surveillance using a social network people search that gathers data about someone’s online activity. 

Open Source Intelligence (OSINT)

Every private investigation involves gathering intelligence about something or someone, which is essentially information that is analyzed and interpreted for evidence. In PI fiction, intelligence is often gathered from wiretaps and computer hacking. In reality, private investigators use more accessible techniques to gather intelligence, like Open Source Intelligence (OSINT). OSINT is a specific type of intelligence that is gathered from open sources, meaning sources that are available to the general public. Open source intelligence techniques help investigators uncover patterns and find evidence for every type of investigation from forensic investigations to business background investigations.

Open source intelligence is one of the best investigation techniques because not only is it effective, but it is also accessible. Private investigators can gather open source intelligence from media sources, academic sources, the internet, or people public records. One common open source intelligence technique is using a criminal record database to uncover someone’s past criminal history for background investigation. Investigators may also use open sources like property records to locate a person, or search business records to gather evidence for a discover fraud investigation.

Due diligence

Even if you’ve never read into private investigation, you’ve likely heard of the term due diligence. Due diligence can be used in a number of different circumstances, but it is typically defined as the analysis of a person or business to uncover any risks before performing a certain action or transaction in order to reduce liability issues from occurring later on. 

So when is due diligence specifically used? Most commonly, a business or individual will perform due diligence on another business before investing in, purchasing, or signing a contract with that business. Due diligence can be complicated — you need to look at a variety of different risk factors in order to conduct proper due diligence, including employees, vendors, customers, owners, finances, and general history. Because of this, many people and businesses hire investigators to help cross everything off the list for a due diligence investigation. 

Investigators may use a variety of different due diligence tools to perform a due diligence investigation. One of the most common tactics of due diligence is searching business records and assets to gain insight into a business’s finances, credit, and payment history and verify the information that is provided by the business. Private investigators may also perform background investigations on key players in a business to determine if they have any shady history, or use big data search engine tools to get a more complete picture of how the business functions. Once a private investigator has performed a due diligence investigation for someone, that individual or entity can make more informed decisions about what to do next. 


Pretext is the act of disguising your identity or pretenses in order to gather evidence for an investigation. It is often used to make contact or get closer to a suspect without raising any concern from the subject. If the subject believes the investigator to be someone else without any specific intentions, the subject may be more likely to talk to the investigator or share certain pieces of information.

One example of pretexting is going to the home of a subject to determine if they are there and pretending to be a mailman or pizza delivery worker who went to the wrong address. Or, investigators may call a subject on the phone and ask questions under the pretense that they are gathering information for a survey. 

Pretexting can be controversial. Certain types of pretexting are illegal, like obtaining sensitive records (like medical records) from a company under false pretenses. However, investigators usually use pretexting to gather more basic information, like determine whether or not someone is home.


When an investigator is “burned” it means that a subject who an investigator is conducting surveillance on has become aware of the investigator’s presence or that they are being surveyed. When an investigator gets burned, they can either end the surveillance and leave or continue to conduct surveillance even though the subject is aware of their presence.

If any investigator continues to conduct surveillance after being burned, it is considered rough shadowing. Investigators want to avoid rough shadowing as much as possible because it makes the subject uncomfortable and can, in certain cases, get them in legal trouble for harassment.


Canvassing is a systematic approach to screening or documenting certain things in an area to gather evidence for an investigation. For example, an investigator may canvass an area and talk to people in that area to identify potential witnesses or suspects. 

One of the most common types of canvassing is a neighborhood canvass. A neighborhood canvass involves interviewing everyone who lives in the neighborhood where a crime took place to gather evidence of the crime or identify a new witness or suspect. of a crime potential witnesses or suspects to gather information. Another type of canvassing is a vehicle canvass, which is when an investigator documents vehicles in a specific area (often the area of a crime) to determine which vehicle belongs to the suspect and the location it is in. 

Counter surveillance

When a subject becomes aware of surveillance and the investigator gets burned, the subject may perform counter surveillance. Counter surveillance is, as the name implies, a counter act to make surveillance difficult or completely destroy a surveillance attempt. For example, a subject may hide out at a friend or family member’s house if they realize an investigator is conducting  physical surveillance on them at their own home.

Another type of counter surveillance is sweeping. If an investigator is conducting technical surveillance with hidden cameras or listening devices and a subject becomes aware, they may perform a sweep of the area. Sweeping involves finding and removing hidden cameras or recorders.

Geographic profiling

Every so often, investigators get hired to investigate multiple connected crimes, and they may use geographic profiling as one of their tactics.  Geographic profiling is a strategy used to determine the location that a suspect lives at. It is commonly done by mapping out and analyzing the exact locations of a series of crimes to make connections between those locations and come to a conclusion about where the most likely area is for a suspect to live. 

Geographic profiling is most commonly used when an investigator believes the suspect to be a serial offender who has committed multiple different crimes. Usually, geographic profiling doesn’t solve a crime, but it does usually help an investigator narrow down the investigation down and identify potential suspects — which is particularly important if the investigator is trying to investigate multiple crimes and dealing with huge amounts of information.

If you’d like to learn more about private investigation, check out our blog post on tips for private investigators. If you’re interested in seeing one of the best private investigator tools in action, get started with Tracers today

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