How Private Investigators Work

Sherlock Holmes is one of the world's most famous fictional detectives.
Photo courtesy Stock.xchng

TĀ­hanks to books, movies and TV shows, many people have a clear mental image of the stereotypical private investigator. He works from a dimly-lit, cluttered, sometimes smoky office in a less-than-affluent part of town. There, he greets a series of walk-in clients -- often women -- who have been wronged in one way or another.

Usually, his job is either to find proof of wrongdoing or to make the situation right again. To do this, he gets useful information from witnesses and bystanders, sometimes with the help of false pretenses and fake identification. He tails witnesses, takes pictures, searches buildings and keeps an eye out for clues that others may have overlooked. Occasionally, his curiosity gets him into trouble, and he barely escapes being caught somewhere he isn't supposed to be. But eventually, he returns to his distressed client, letting her know that he's solved the case.


Lots of fictional detectives have contributed to this image, including Sherlock Holmes, Philip Marlowe and multiple film noir heroes from the 1940s and 50s. Today's pop-culture investigators, like Adrian Monk and Veronica Mars, are often a little quirkier than their older counterparts. They don't necessarily wear fedoras, work in questionable neighborhoods or even call themselves private investigators. However, they still appear as heroes who have a knack for digging up the right information at the right time.

But just how much of the P.I. lore is really true? How many of the events depicted in fiction are really possible -- or legal? In this article, we'll explore what it takes to become a private investigator and exactly what the job involves.

The first step to separating fact from fiction is to define precisely what a private investigator is. Essentially, private investigators are people who are paid to gather facts. Unlike police detectives or crime-scene investigators, they usually work for private citizens or businesses rather than for the government. Although they sometimes help solve crimes, they are not law-enforcement officials. Their job is to collect information, not to arrest or prosecute criminals.

The term "private eye" comes from the Pinkerton Detective Agency logo
Public domain image

Private investigators have existed for more than 150 years. The first known private detective agency opened in France in 1833. In 1850, Allan Pinkerton formed Pinkerton National Detective Agency, which grew into one of the most famous detective agencies in the United States. The Pinkerton Agency became notorious for breaking strikes, but it also made several contributions to the fields of law enforcement and investigation. The agency takes credit for the concept of the mug shot, and the term "private eye" came from the original Pinkerton logo.

Today, about a quarter of the private investigators in the United States are self-employed. Of those who are not, about a quarter work for detective agencies and security services [source: U.S. bureau of Labor Statistics]. The rest work for financial institutions, credit collection services and other businesses. Many investigators choose to focus on a specific field of investigation based on their background and training. For example, someone with a degree in business might become a corporate investigator. An investigator with a background in patents and trademarks might focus on intellectual property theft. A certified public accountant (CPA) might specialize in financial investigation.

But regardless of specialization, a P.I.'s job is to conduct thorough investigations. We'll look at the investigative process in the next section.


Conducting Investigations

In many detective movies, the typical client is a damsel in distress.
Photo courtesy Amazon

The stereotypical private investigator comes from books, TV and movies -- so does the stereotypical client. In the world of fictional investigators, clients often turn to investigators for help because the information they seek doesn't fall within police jurisdiction. They may also be afraid or unable to ask the police for help. In some portrayals, clients have already tried to work with law-enforcement agencies but aren't happy with the result. Often, fictional clients are looking for:

  • Lost or stolen property
  • Proof that a spouse or partner is unfaithful
  • Proof that a friend or business associate is dishonest
  • Missing friends or relatives
  • The perpetrator in an unsolved crime

Although real clients aren't the archetypal damsels in distress that appear in fiction, the types of cases that surface most often in movies and books are also common in real life. A real investigator's caseload often includes background investigations, surveillance and skip traces, or searches for missing people. Investigators may also serve legal documents, notifying people of their involvement in legal proceedings. In the United States, this is part of the due process guaranteed in the Fifth and 14th Amendments to the Constitution.


Naturally, day-to-day duties vary depending on a detective's expertise. Someone who specializes in intellectual property theft will spend far more time studying patents than staking out hotels looking for errant spouses. Some cases are also more common in specific regions. For example, in New York City, some landlords hire private investigators to determine whether tenants in rent-controlled apartments are violating their lease terms. The investigators look for physical proof of violations like subletting apartments and living elsewhere or using residential units for business purposes. [Source: New York Times].

Finding the perpetrator in an unsolved crime might not seem to have much in common with running a background check or finding grounds for a tenant's eviction. But they all involve the same basic task -- in order to solve any case, a private investigator has to collect and organize facts.

Gathering facts involves more than the luck and intuition that some fictional investigators seem to rely on. Successfully solving a case begins with planning and analysis. The investigator must:

  • Discuss the case with the client and determine whether it is legal, ethical and possible to solve.
  • Work out a plan and budget for gathering the necessary information.
  • Conduct the investigation, gathering evidence in such a way that it can be presented in court when necessary.
  • Analyze the evidence.
  • Report to the client with findings.

Like any good researcher, a private investigator uses multiple sources of information to solve a case. The source most commonly associated with private investigators is surveillance. The basic idea behind surveillance is very simple -- the investigator follows a target and documents where he goes and who he meets. Actually conducting surveillance can be far more difficult. Following people without losing them or being noticed is a difficult skill to master. While some affluent investigation agencies have sophisticated surveillance vans, many investigators simply work from their cars. The process of watching someone can also be long and tedious with no possibility for breaks.

Surveillance often involves skill with a camera and long hours in the car.
Photo courtesy Stockexpert

Researchers can also interview suspects and witnesses. In general, the person being interviewed has no legal obligation to speak to the investigator. For this reason, the process often involves time devoted to building rapport and making the interviewee comfortable. In addition, some investigators use pretexts or ruses to get information from people who might otherwise be reluctant to talk to them. Using false pretenses to gain information can have legal and ethical implications -- see "Private Investigation and the Law" to learn more.

Public records are another source of information. Many of these are records that private citizens can access on their own. However, private investigators generally know who to ask and how to access the information easily. In some cases, private investigators can access databases that search multiple record sources at once. These databases are not usually available to the general public. The records investigators often search include:

  • Tax records
  • Real estate transactions
  • Records of births and deaths
  • Court records
  • Voter registrations
  • Business licenses
  • Vital statistics records
  • DMV records

In addition to gathering information, private investigators must know how to analyze it and present it to their clients. Along with the investigative techniques that they use to gather information, this skill is part of their investigative training. We'll look at training and licensing procedures for private investigators in the next section.


Training and Licensing

Many people who decide to become private investigators already have experience in a related field. They may have served in a branch of the military or worked as police officers. Others have experience in crime-scene investigation or surveillance. While this experience can be helpful, it doesn't entirely replace education and training.

In most cases, a person learns to be a private investigator through apprenticeship with an experienced investigator or formal instruction. Either on the job or in a classroom, the future investigator learns about:


  • Planning and coordinating investigations
  • Investigative and surveillance techniques
  • Laws and ethics pertaining to investigative practice
  • Questioning witnesses
  • Evidence-handling procedures

Some investigators also use DVDs and distance-learning programs to continue their educations.

In many parts of the world, education and training are only a first step -- becoming a private investigator also requires applying for and obtaining a license. But the process a person has to go through, or whether licensure even exists, varies from place to place. England and Wales, for example, have no official licensing procedure. However, the Security Industry Authority, which regulates private security in Great Britain, conducted research in 2005 and 2006 which may eventually lead to licensure for private investigators.

In the United States, each state has its own licensing requirements. Alabama, Alaska, Colorado, Idaho, Mississippi, Missouri and South Dakota have no statewide licensing procedure. Most other states require some combination of education and training and a clean criminal record. Some states also require schools to submit their curricula and meet specific criteria for state approval. In those states, only people whose education comes from an accredited school can become a licensed investigator.

The length of study and exact steps required to obtain a license vary considerably. In California, applicants must complete specific educational courses and pass a written exam. The terminology can also differ -- in Massachusetts, private detectives hold state licenses, but private investigators do not. Some states require investigators to have liability insurance. Finally, some states allow private investigators to carry firearms. Generally, this requires the investigator to apply for and receive a weapon permit.

Having a license allows a private investigator to practice in one particular state, but the nature of investigative work can require investigators to cross state lines. Some states have reciprocity agreements with one another -- a license in one state allows a person to practice in the other as well. Investigators practicing in states without such agreements sometimes apply for licensure in nearby states as well. Others develop working relationships with investigators in other states, working as assistants, apprentices or trainees when traveling.

While licenses give people the right to present themselves as private investigators, they do not give people the right to break the law in the course of investigations. We'll look at the legal and ethical issues surrounding private investigation in the next section.


Private Investigation and the Law

Photo courtesy National Library of Medicine

Reading books and watching movies about private investigators naturally requires some suspension of disbelief. After all, many fictional detectives are impossibly heroic or improbably cool. But fictional investigators aren't just too smart, too good-looking, too lucky or too witty to be true. Much of the time, they make decisions that would land a real investigator in jail and out of a job.

When a TV private eye dons a cap with a cable company's logo, picks up a clipboard, and pretends to have questions about when a neighbor will be home, he's using a ruse to get information. This technique has become known as pretexting, and while it isn't always illegal, critics argue that it is often unethical. Others contend that the ends can justify the means -- if using a disguise and fake identification leads to an arrest, then the ruse is worth the risk.


However, in some cases, pretexting is against the law:

  • In most parts of the world, falsely presenting oneself as a law-enforcement official, a government employee or an attorney is illegal.
  • In the United States, using pretexts to gain access to a person's telephone records or to get information from a financial institution is a violation of Federal law.

Another common scenario in detective stories involves trespassing or breaking and entering. In many countries, entering private property without the permission of the owner or tenant is illegal. For this reason, private investigators typically conduct surveillance from public property to avoid legal issues. In many jurisdictions, the surveillance itself is legal, especially if the investigator has notified the police of his presence. Private phone surveillance using recording devices or wiretapping, on the other hand, is usually illegal.

Fictional investigators also sometimes apprehend, detain and interrogate criminals, which could be considered kidnapping. However, in some cases, detaining a criminal might be legal. Some states and countries allow citizens who witness a felony or identify a felon to detain that person. The exact situations in which such citizen arrest is permissible can vary in different jurisdictions.

Some critics feel that private investigators' work is an invasion of people's privacy. A number of laws and constitutional amendments protect people's privacy in many countries throughout the world. However, many of these laws regulate the steps that the government or certain businesses can take. They do not necessarily affect whether a private investigator is permitted to take surveillance photos or to use pretexts to get information that would otherwise be confidential.

Because of privacy concerns and depictions in popular culture, some people believe that private investigators are often on the wrong side of the law. Private investigators have also appeared in a negative light in some high-profile cases, such as the Hewlett-Packard corporate spying trial in 2006 and 2007. However, as more states and countries begin to regulate and license investigators, this perception may gradually begin to change. To learn more about licensing procures, legal issues and how to become a private investigator, check out the links on the next page.


Lots More Information

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More Great Links

  • Advanced Surveillance Group. "History of Private Investigators." (2/7/2007)
  • Bancroft, Melissa C. "Senate Passes Anti-Pretexting Legislation in Wake of HP Scandal." 12/9/2006 (2/7/2007) senate-passes-anti-pretexting.php
  • BBC. "Power of Arrest in England and Wales." (2/7/2007)
  • California Bureau of Security and Investigative Services (2/7/2007)
  • Federal Trade Commission. "Pretexting: Your Personal Information Revealed." (2/7/2007)
  • Federal Trade Commission. "The Gramm-Leach-Bliley Act: Pretexting." (2/7/2007)
  • Office of the Revisor of Statutes, Maine. "Title 32: Private Investigators." 11/2/2006 (2/7/2007)
  • Scott, Janny. "Private Eyes Turn to the Case of Illegal Sublet." New York Times. 1/27/2007 (2/7/2007) res=F70917F93C5B0C748EDDA80894DF404482
  • Security Industry Authority. "Private Investigation." (2/7/2007) private_investigation.htm
  • Security Industry Authority. "SIA Research: Private Investigator Best Practice." October 2006 (2/7/2007) C2EC363E577A/0/sia_pi_best_practise.pdf
  • State of Louisiana. "Private Investigators Law." (2/7/2007)
  • State Requirements for Private Investigator (Detective) Licensing (2/7/2007)
  • Sung, Michael. "Private Investigator in HP Spying Scandal Pleads Guilty to Federal Charges." 1/12/2007.(2/7/2007) private-investigator-in-hp-spying.php
  • U.S. Bureau of Labor Statistics. "Private Detectives and Investigators." 8/4/2006 (2/8/2007)
  • United States Library of Congress. "Today in History: The Pinkertons." (2/7/2007)