Glossary of Investigation Terms and Definitions

Glossary of Investigation Terms
A list of terms related to investigations and law.

This glossary of investigation terms is intended to help private investigators, police officers and everyday citizens understand the meaning of various terms used in investigation work.

During the course of investigation work, private investigators have interactions with police officers to discuss the information contained in police reports. In addition, private eyes work directly with attorneys and lawyers to review court records and discuss court cases. Also, private investigators speak with experts and specialists about such things as forensics, crime scene investigations, and even handwriting analysis.

Having an understanding of these terms and the definitions will help private investigators “speak the language” of their craft. The more well-versed you become in the language of investigations, the more valuable you will become to your clients. It is not your job to take the place of a qualified attorney, but you should be able to “talk the talk”. To begin, familiarize yourself with all of the definitions in this glossary of investigation terms.

If you’re looking for a handy desk reference book, I recommend Merriam-Webster’s Dictionary of Law, Newest Edition, Trade Paperback, available at

List of Investigation Terms and Definitions

Following is a list of some of the most common terms and definitions.


Adultery is the voluntary sexual intercourse between a married person and another person who is not their spouse. In most cases, only the married party is said to have committed adultery. However, if both parties are married (but not to each other) then they both have committed separate acts of adultery. Also, adultery is known as Extramarital sex, philandering, infidelity, or cheating. In addition to cheating, other slang terms include creeping, “on the down-low”, sleeping around, and others.


Arrests and Arrest Warrants

Assault and Battery


A bond is a written, binding agreement to perform something as specified. Many different types of bonds exist and appear in marriage, land, and court records used by genealogists. Historically, laws required administrators and executors of estates, grooms, and guardians of minors to post bonds.  If a bondsman failed to perform, the court may have demanded payment of a specified sum as a penalty.

There is likely to be a bail bond associated with every fugitive you are hired to track and retrieve. In addition, detectives need to be bonded as a part of the licensing requirements in most, if not every state. In this situation, it serves as insurance for a third party, such as the state in which the private eye has a license. It serves as a way of ensuring that the licensed individual properly complies with state laws, statutes, and rules and regulations of their trade.

The cost of obtaining a bond varies from state to state, term periods, coverage amounts, and whether you are an individual or a full-service agency. For more information, see Bail Bonds.


Burglary is the illegal entry into a building or home for the purposes of committing an offense or committing a crime. Usually, the offense committed during a burglary is the theft of property. Individuals burglarize homes, cares, businesses, storage units, and more. Stolen items are often sold at pawn shops or via online marketplaces such as eBay. The crime of burglary consists of two elements: trespass and breaking.

The trespass element indicates the individual’s presence on the property (car, storage unit, etc.) is without the owner’s consent. The breaking element consists of making an opening to enter the building. To commit a burglary is to burgle or to burglarize. Other common names for burglary include Breaking and entering, Housebreaking, Break-in, Home invasion. The punishment for burglary is usually imprisonment. The term of imprisonment depends on the degree of severity of the burglary. For example, greater penalties are given if the burglary involved deadly weapons or if anyone is injured as a result of the crime.

Class Action Lawsuit

A class-action lawsuit is a form of legal action in which a large group of people collectively bring a claim to court and/or in which a class of defendants is being sued. Class action lawsuits are most often seen in relation to pharmaceuticals and drug companies, usually related to injuries or deaths associated with a particular product or drug. In other cases, many public companies face class-action suits related to the trading of their stock and dividend matters.

Class action lawsuits may appear to offer an advantage to individual plaintiffs because they aggregate a large number of individualized claims into one representational lawsuit. However, if a lawsuit is won against the defendant, the plaintiffs in the case usually only receive a very small amount of compensation. It is usually the attorneys and legal teams that end up making millions.

Many people who receive a notice of a class-action lawsuit in the mail do not complete the steps necessary to make a claim. The attorneys and lawyers involved in the process make the claims process unnecessarily confusing and laborious. This is seemingly in an attempt to reduce the number of claims made by individuals. This results in a larger pot of money for others, especially the legal group involved in administering the suit.


A conspiracy is defined as an agreement between two or more persons to break the law at some time in the future. In other words, they “conspire” to commit a crime together. In some cases, a conspiracy requires there to be at least one overt act in furtherance of the agreement to commit a crime.

For example, furtherance may include the purchase of supplies or materials, visiting or “scoping” the location, or documenting plans for the act. However, in most countries, there is no requirement that any steps be taken to put the conspiracy plan into an effort for it to be considered unlawful.

There is no limit on the number of people who might participate in the planning or execution of the conspiracy. In some situations, only two people are required to qualify. In others, small groups or even organized gangs may be involved. Also, entire organizations or even military organizations could be involved in the planning and execution of the act.

Copyright Infringement

Copyright infringement (or copyright violation) is the unauthorized use of material that is covered by copyright law, in a manner that violates one of the copyright owner’s exclusive rights, such as the right to reproduce or perform the copyrighted work, or to make derivative works. For electronic and audio-visual media, unauthorized reproduction and distribution are occasionally referred to as piracy. If you need to research copyright laws, the best place to start is the U.S. Copyright Office. The U.S. Copyright Office website is an excellent resource for learning and understanding copyrighting and related laws.


Crime is the breach or breaking of one or more rules or laws for which some governing authority deems as unlawful. While every crime violates the law, not every violation of the law counts as a crime. For example, breaches of contract and of other civil law may rank as “offenses” or as “infractions” but are not considered to be a crime.

Crime usually includes those activities considered to be harmful to the general population or to the state, including crimes that cause serious loss or damage to individuals.


Criminology involves the study of crime related to individuals and society. The research also includes social and governmental regulations and reactions to crime. A criminologist is someone who studies crime. Criminologists often work for law enforcement agencies or departments. They work with historical data and information to analyze the behavior and methods used by criminals. Criminologists attempt to identify patterns, trends, and motives to increase the likelihood of apprehending criminals.

Defendants on Plaintiffs


Detention is the process of keeping a person who has been arrested in a jail cell, prison, or another detention center before their legal trial or sentencing. Such buildings are often referred to as detention centers or detention facilities. People can also be detained illegally or against their will. In this situation, crimes such as kidnapping or unlawful arrest may occur.



Embezzlement is the act of dishonestly taking financial assets from another in a manner designed to conceal the activity and avoid detection.



The definition of extortion is a criminal offense that occurs when a person uses coercion to unlawfully obtains either money, property, or services from a person, entity, or institution. It is a crime that is commonly practiced by organized crime groups. If the act is committed using a  computer system, phone, by mail, or in using any instrument of “interstate commerce”, then it is a federal crime.

False imprisonment

False imprisonment is a tort, and possibly a crime, where a person or multiple persons are intentionally confined by another person or persons without legal authority. It entails the restraint of an individual or the obstruction of their freedom without their consent. The imprisonment of another can take many forms, such as being locked in a room or car, tied to a chair, etc.

The elements of false imprisonment usually involve:

  • The person detained is being held against their will
  • The imprisoned person is unable to move about freely
  • Proof can be provided that the imprisonment was not lawful

Although punishment may vary from country to country, and even state to state, it is generally considered to be a 3rd-degree felony, which carries penalties such as up to five years in jail, a fine of up to $5,000, probation, community service, other penalties as defined by the court. If false imprisonment can be proved, damages may be awarded in civil court. The term false arrest is sometimes used in relation to false imprisonment, but it actually has a different meaning.

Under a false arrest, one person arrests another, but the arresting person does not have legal justification or legal authority to do so. If the arresting person takes the other into custody and restricts their freedom, then it also becomes false imprisonment.

Family Law

Family Law – Includes an overview of Alimony, Child Support, and Legal Guardianship


A felony is defined as a serious crime. Felonies are generally considered to be the most serious type of crime. The term felony originates from English common law where felonies were originally crimes that involved the confiscation of a convicted person’s land and goods. Following are examples of some of the more common types of felonies:

  • Homicide, murder
  • Kidnapping
  • Burglary
  • Grand theft
  • Grand larceny
  • Drug abuse violations
  • Automobile theft
  • Arson
  • Assault
  • Disorderly conduct
  • Domestic violence
  • Child abuse
  • Forgery
  • Counterfeiting

The Federal government defines a felony as a crime that involves a potential punishment of one year or longer in prison.

Grand Larceny

Grand larceny is the crime of theft of another’s property (including money) that exceeds a certain value (for example, $500). The crime is distinguished from petty (or petit) larceny in which the value is below the grand larceny limit. Some states only recognize the crime of larceny, but draw the line between a felony (punishable by state prison time) and a misdemeanor (local jail and/or fine) based on the amount of the money.

Habeas Corpus

Habeus Corpus is a writ that requires a person who is under arrest to be brought into court before a judge, usually to secure the person’s release from arrest, unless lawful grounds for their arrest can be provided.

Involuntary Manslaughter

Involuntary Manslaughter is defined as the crime of killing another human being in an unlawful manner but unintentionally.

Judges and Juries

Juvenile Delinquency



A larceny is a form of theft. Larceny involves the taking and carrying away of personal property without the owner’s consent. The terms “petty larceny” and “grand larceny” refer to the value of items that were taken.


The definition of a lawsuit is a civil action brought in a court of law in which a plaintiff. The plaintiff is a party who claims to have incurred loss as a result of a defendant’s actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff’s complaint. If the plaintiff is successful, judgment will be given in the plaintiff’s favor, and a variety of court orders may be issued to enforce a right, award damages, or impose a temporary or permanent injunction to prevent an act or compel an act.


Manslaughter is defined as the crime of killing a human being without malice aforethought, or otherwise in circumstances not resulting in murder.


A misdemeanor is generally considered to be a “lesser” or minor criminal act. Misdemeanors are generally punished much less severely than felonies. Many are punished with monetary fines and do not involve a prison sentence or jail time to be served.

The federal government generally considers a crime punishable with incarceration for one year or less to be a misdemeanor. All other crimes are considered to be felonies. Many states also follow this same view of this type of crime. Depending on the jurisdiction, examples of misdemeanors may include:

  • Petty theft, stealing items of low value
  • Prostitution or selling sexual favors
  • Public intoxication or drunkenness
  • Simple assault
  • Disorderly conduct
  • Trespassing
  • Vandalism
  • Drug possession
  • Driving under the influence (DUI)
  • other similar crimes

Misdemeanors are crimes with a maximum punishment of 12 months of incarceration. Incarceration typically takes place in a local jail, rather than a state or federal prison facility. In contrast, felons (those who are convicted of committing a felony crime) are usually incarcerated in a state or federal prison. Most often, those convicted of misdemeanors are punished with probation, community service or part-time imprisonment, served on the weekends, pay a monetary fine, or some combination of each.

Mug Shots

  • Mug Shots – Photos taken of arrested individuals

Nolo Contendere

Nolo contendere is a Latin legal term that simply stands for “I do not wish to contend.”  Nolo contendere is also referred to as a plea of “no contest” and is often referred to as “pleading nolo.” In criminal court trials, Nolo contendere is a legal plea made by the defendant who does not admit to committing a criminal charge, nor do they dispute the charge.


A paralegal is a term used to describe people who assist lawyers in their legal work. The profession originated as an assistant or secretary who provided assistance to lawyers with legal matters, research, and related matters. Paralegals are not lawyers, but generally do have considerable knowledge, education, and even certification in legal matters and law.

  • Paralegals are not authorized by the government to offer legal services such as those provided by an attorney or lawyer
  • They are not considered to be officers of the court (i.e. considered a formal part of the legal system)
  • They are not usually subject to government or court-sanctioned rules of conduct
  • Paralegals usually work under the direct supervision of a lawyer


Perjury is officially defined as the willful act of swearing a false oath or affirmation, to tell the truth concerning matters material to a judicial proceeding.  The act of perjury can be either spoken or written, but is most commonly committed as part of spoken testimony in a court case.

During court proceedings that involve witnesses, each witness that testifies must swear under oath that they will tell the honest truth. Oaths are taken during court in front of the judge and often in front of a jury. Witnesses are not forced or coerced to take the oath, but it is required. When a witness commits perjury, they falsely promise to tell the truth about matters which affect the outcome of the case.

The exact wording of the oath may vary from country to country, and even from state to state. Following is an example of the typical oath used in the United States: “Do you solemnly swear or affirm that you will tell the truth, the whole truth, and nothing but the truth, so help you, God?” The court bailiff usually swears in the witness and the witness usually places their hand on a bible as they agree to the oath.

When a person is charged and convicted of perjury, they may face criminal charges in the form of a financial fine or, in more serious cases, may serve jail time. Each state has its own laws and penalties regarding this crime.

Petty Larceny

Petty larceny is a term used for theft of a small amount of money or items that have little value (such as less than $500). Petty larceny is considered to be a misdemeanor and is usually punishable at maximum with a term in the county jail. States which only use the term “larceny,” often treat theft of smaller amounts as a misdemeanor in sentencing.

Probable Cause

Probable cause is the standard by which a police officer has the right to make an arrest, conduct a personal or property search, or to obtain an arrest warrant. A police officer must have probable cause to arrest someone. Probable cause is also used to refer to the standard to which a grand jury believes that a crime has been committed.


Restraining Order

A form of legal injunction that is most commonly used in reference to domestic violence, harassment, stalking or sexual assault. Each state has some form of domestic violence restraining order law, and many states also have specific laws for stalking and sexual assault. Orders are issued by a state court and may also be referred to as Protection Order, Order of Protection, Protection from Abuse Order, etc.

Search and Seizure

Search and seizure is a legal procedure where a law enforcement officer who suspects that a crime has been committed, can perform a full visual and physical search of a person’s property and confiscate any relevant evidence to the crime.

Search Warrant

Sexual Assault


A crime that consists of a situation where a person offers money or something else of value in order to incite or induce another to commit a crime with the specific intent that the person solicited commit the crime. Basically, it is convincing someone else to do something illegal.

This can be accomplished in a variety of ways. Other definitions of Solicitation include: To entice or incite to take evil or illegal action; To approach or accost (a person) with an offer of sexual services; To make solicitation or petition for something desired; To approach or to accost someone with an offer of sexual services in return for financial. Situations involving solicitation are most common in relation to prostitution. Prostitutes are said to have “solicited” sex.

Stand-Your-Ground and No Duty to Retreat Laws

The highly controversial stand-your-ground law states that a person may use force in self-defense when there is a reasonable belief of a threat, without an obligation to try to retreat or getaway first.  In some stand your ground cases, a person may use deadly force in public areas without having a duty to retreat.

Under these legal concepts, a person is justified to use deadly force in certain situations and the “stand your ground” law would be a defense to criminal charges and a civil suit.

In general, the law is designed to protect individuals who feel their life may be in danger. In some situations, some people would hesitate to use lethal force to protect themselves for fear of lethal consequences. These laws basically say that you can use whatever force that you deem necessary at the moment if you feel that your life is in danger. The statutes are also referred to as a “line in the sand” or “no duty to retreat”.

The following states have such laws:

  • Alabama
  • Alaska
  • Arizona
  • California
  • Florida
  • Georgia
  • Illinois
  • Indiana
  • Iowa
  • Kansas
  • Kentucky
  • Louisiana
  • Maine
  • Michigan
  • Mississippi
  • Missouri
  • Montana
  • New Hampshire
  • North Carolina
  • North Dakota
  • Ohio
  • Oklahoma
  • Pennsylvania
  • Rhode Island
  • South Carolina
  • South Dakota
  • Tennessee
  • Texas
  • Utah
  • West Virginia


A statement is a formal account of the facts related to a case. A statement is given by a witness, defendant or other party related to a case in a court of law.

Statute of Limitations

A legal statute that sets forth the maximum period of time after certain events have occurred, that legal proceedings based on those events may be initiated. Basically, what this means is that after a certain length of time, you may not be able to sue someone in a court of law if the limitation has been exceeded. Also, someone may not be prosecuted for a crime after the period has expired.


Subrogation refers to circumstances in which an insurance company tries to recover expenses for an insurance claim it paid when another party was responsible for payment of the insurance claim.  Types of subrogation include:

  • Indemnity insurer’s rights
  • Surety’s rights
  • Rights of business creditors
  • Lender’s rights
  • Banker’s rights

Subpoenas and Summons

A summons is a legal document issued by a court that announces that a legal proceeding has been started against the person to whom it is issued.


A suspect is a person who is believed by law enforcement of committing a crime. Police officers and media reporters often use the term suspect incorrectly when they refer to the actual perpetrator (perp) of the crime or criminal offense. The perpetrator (one who perpetrates) is the person who actually commits the crime.

The perpetrator is the thief, the bank robber, the assailant, the illegal counterfeiter, etc. The distinction between suspect and perpetrator is that the suspect is not known to have committed the offense. The person is only “suspected” to have committed the crime, while the perpetrator is the person who actually did.


Legal testimony is a form of evidence that is obtained from a witness who makes a solemn statement or declaration of fact. Testimony may be oral or written, and it is usually made by oath or affirmation under penalty of perjury. Unless a witness is testifying as an expert witness, testimony in the form of opinions or inferences is generally limited to those opinions or inferences that are rationally based on the perceptions of the witness and are helpful to a clear understanding of the witness’ testimony.

Expert testimony – An expert witness provides their opinion about facts and conclusions within their field of expertise.


Theft, in its simplest terms, is stealing. Theft occurs when a person takes or steals, property or items that do not belong to them.  Theft is often used as an informal term for crimes against property, such as:

  • Burglary, embezzlement, larceny, looting, robbery, shoplifting, fraud, criminal conversion

In some jurisdictions, theft is considered to be synonymous with larceny; in others, the crime of theft has replaced that of larceny. Someone who carries out an act of or makes a career of theft is known as a thief.


A tort is a wrong that involves a breach of a civil duty owed to someone else. It is differentiated from a crime, which involves a breach of a duty owed to society in general. The term “tort” is derived from the Latin word “tortum” which means crooked or something twisted. The acts of nuisance, negligence, defamation, assault, trespass, property damage are considered to be torts. Some are also considered to be crimes and are punishable with imprisonment.

The primary goal of this law is to provide the victim with relief from the damages and to serve as an example to deter others from committing this type of crime. In the case of the tort the injured person may also be sued for monetary damages and injunction to prevent the tortuous act. In addition, the injured party may recover some kind of damages like reasonable medical expenses, pain and suffering and loss or earnings during that period. Torts can be generally classified into three categories:

  • Intentional – In this case, an act is done intentionally to harm someone. In this situation, the defendant is aware or should have been reasonably aware, that the action or inaction could prove to be harmful to others.
  • Negligent – These normally occur when the actions of the defendant are considered to be unsafe.
  • Strict Liability – These types of torts generally apply to defective products.

Wire Tapping

Related Information

  • If you need legal forms related to any of the above, see a full list of legal forms at
  • Also, see our list of Acronyms related to the legal field, law enforcement, and the investigation industry.

Legal Dictionary

If you need more details on anything in this glossary of investigation terms, visit the legal dictionary on

Questions about this Glossary of Investigation Terms

If you have any questions about this glossary of investigation terms and definitions, please leave a comment below.

Michael Kissiah is the owner of Brandy Lane Publishing, LLC, which owns and operates a small portfolio of websites, including Michael created more than 20 years ago after working as a private investigator in the state of Florida. Since that time, he has become an expert at how to find information online and has written over 1000 articles on topics related to the investigation industry. In addition, he is the author of the "Private Investigator Licensing Handbook", available at


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