Legal Glossary

A judgment of not guilty in a criminal trial. An acquittal means the prosecution failed to prove the defendant's guilt beyond a reasonable doubt. Once acquitted, a defendant cannot be retried for the same offense due to the Double Jeopardy Clause.

A court proceeding in which a criminal defendant is formally advised of the charges against them and asked to enter a plea (guilty, not guilty, or no contest). It is typically the first court appearance after an arrest.

The act of taking a person into police custody, depriving them of their freedom of movement. An arrest requires probable cause — a reasonable belief that the person has committed or is committing a crime. Officers must identify themselves and state the reason for the arrest.

A written order issued by a judge or magistrate authorizing law enforcement to arrest a specific individual. The warrant must be based on probable cause supported by an oath or affirmation describing the person and the alleged offense.

A written statement of facts confirmed by the oath of the party making it, before a notary or officer authorized to administer oaths. Affidavits are used to support warrant applications, motions, and other court filings. They carry the penalty of perjury if the statements are knowingly false.

A warrant issued directly by a judge (from the bench) for the arrest of a person who has failed to appear in court as required, violated probation, or failed to comply with a court order. Unlike arrest warrants, bench warrants do not require a police application — they are issued at the judge's discretion.

Money or property deposited with the court to secure a defendant's release from custody, ensuring they will appear for future court proceedings. The Eighth Amendment prohibits excessive bail. Bail amounts are set by a judge based on the severity of the charges, flight risk, and community ties.

A wearable audio and video recording device used by law enforcement officers to document interactions with the public. Body camera footage can serve as critical evidence in complaints, lawsuits, and criminal proceedings. Policies on when cameras must be activated vary by department.

Evidence favorable to the defendant that the prosecution is constitutionally required to disclose. Named after the Supreme Court case Brady v. Maryland (1963), this includes any evidence that could prove innocence, reduce the severity of the offense, or impeach a prosecution witness.

The obligation to prove allegations or claims in a legal proceeding. In criminal cases, the prosecution bears the burden of proving the defendant's guilt "beyond a reasonable doubt" — the highest standard of proof in the legal system. The defendant is presumed innocent until proven guilty.

A legal principle that designates a person's home (and sometimes vehicle or workplace) as a place where they have certain protections and immunities, including the right to use force — sometimes deadly force — to defend against intruders. Laws vary significantly by state.

The documented, chronological history of evidence showing who collected, handled, transferred, analyzed, and stored it. A proper chain of custody ensures evidence has not been tampered with or contaminated. Any break in the chain can render evidence inadmissible in court.

The rights of individuals to receive equal treatment and be free from discrimination and unfair treatment by the government. Civil rights are guaranteed by the Constitution and federal laws such as the Civil Rights Act of 1964. They include protections against discrimination based on race, color, religion, sex, and national origin.

A search conducted by law enforcement after receiving voluntary permission from the individual. When you consent to a search, you waive your Fourth Amendment protections. Consent must be given freely and voluntarily, without coercion, threats, or deception by officers.

A right guaranteed to individuals by the United States Constitution and its amendments. These rights limit the power of the government and protect individual liberties. Key constitutional rights relevant to police encounters include protection against unreasonable searches (4th Amendment), the right to remain silent (5th Amendment), and the right to counsel (6th Amendment).

Questioning initiated by law enforcement after a person has been taken into custody or otherwise deprived of their freedom in any significant way. Miranda warnings must be given before custodial interrogation begins. Any statements obtained without Miranda warnings during custodial interrogation are generally inadmissible in court.

An act of disobedience or disrespect toward a court or its proceedings. Contempt can be civil (failure to comply with a court order) or criminal (disrupting court proceedings). Penalties include fines and imprisonment. Judges have broad discretion in holding individuals in contempt.

An independent oversight body composed of community members that reviews complaints against police officers and investigates allegations of misconduct. Civilian review boards vary in their authority — some can only recommend discipline, while others have subpoena power and binding authority over disciplinary decisions.

A camera mounted on the dashboard of a police vehicle that records interactions during traffic stops and pursuits. Dashcam footage provides an objective record of events and can be critical evidence in court proceedings, complaint investigations, and civil rights lawsuits.

A witness's sworn out-of-court testimony that is recorded for later use in court proceedings. Depositions are part of the discovery process and allow attorneys to gather information and preserve testimony. The witness is under oath and the testimony can be used at trial.

The pre-trial process in which both parties exchange relevant information and evidence. Discovery includes depositions, interrogatories, requests for documents, and requests for admissions. This process ensures both sides have access to the facts before trial.

The Fifth Amendment prohibition against being tried twice for the same offense after an acquittal or conviction. This protection prevents the government from repeatedly prosecuting a person for the same crime, ensuring finality and protecting individuals from the stress and expense of multiple trials.

The constitutional guarantee (under the Fifth and Fourteenth Amendments) that the government must respect all legal rights owed to a person. Due process includes both procedural due process (fair procedures) and substantive due process (protection of fundamental rights). No person shall be deprived of life, liberty, or property without due process of law.

The use of more physical force than is reasonably necessary to accomplish a lawful police objective. Under Graham v. Connor (1989), courts evaluate excessive force claims using an "objective reasonableness" standard, considering the severity of the crime, whether the suspect posed an immediate threat, and whether the suspect was actively resisting.

Evidence that tends to establish a defendant's innocence or reduce their culpability. Under the Brady v. Maryland ruling, prosecutors have a constitutional obligation to disclose exculpatory evidence to the defense. This includes witness statements, forensic evidence, and any material that could benefit the defendant.

Emergency situations that allow law enforcement to act without a warrant. Examples include imminent danger to life, the destruction of evidence, hot pursuit of a fleeing suspect, or the escape of a suspect. The Supreme Court has held that these exceptions must be narrowly applied.

The legal process of sealing or destroying criminal records so they are no longer accessible through state or federal databases. Expungement eligibility varies by state and typically depends on the type of offense, time elapsed, and the individual's subsequent criminal history.

An arrest made without proper legal authority or probable cause. False arrest is both a crime and a civil tort, meaning the arresting officer and their department can be sued for damages. The Fourth Amendment protects against false arrest by requiring probable cause.

The unlawful restraint of a person's freedom of movement. Unlike false arrest, false imprisonment does not require a formal arrest — it can occur when police unlawfully detain someone beyond a reasonable time without justification. This includes being held in a police car or interrogation room without cause.

A serious criminal offense typically punishable by imprisonment for more than one year. Felonies include crimes such as murder, robbery, aggravated assault, and drug trafficking. Felony convictions carry significant consequences including loss of voting rights, firearm ownership restrictions, and difficulty finding employment.

A series of physical and cognitive tests administered roadside by law enforcement to assess whether a driver is impaired. Standard tests include the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn, and One-Leg Stand. These tests are voluntary in most states and are used to establish probable cause for a DUI arrest.

The First Amendment to the U.S. Constitution protects freedoms of speech, press, religion, assembly, and the right to petition the government. Courts have consistently held that the First Amendment protects the right to record police performing their duties in public spaces.

A framework used by law enforcement agencies that outlines the levels of force appropriate for various situations. The continuum typically ranges from officer presence (lowest) through verbal commands, physical control, less-lethal weapons, to deadly force (highest). Officers are trained to use the minimum force necessary.

The Fourth Amendment to the U.S. Constitution protects people against unreasonable searches and seizures by the government. It requires law enforcement to obtain warrants based on probable cause, supported by oath or affirmation, and particularly describing the place to be searched and the persons or things to be seized.

The Fifth Amendment protects against self-incrimination, double jeopardy, and deprivation of life, liberty, or property without due process of law. It also requires a grand jury indictment for serious federal crimes and guarantees just compensation for property taken by the government (eminent domain).

The Fourteenth Amendment guarantees equal protection under the law and extends due process protections to actions by state and local governments. Its Equal Protection Clause prohibits states from denying any person equal protection of the laws, and its Due Process Clause has been used to apply most of the Bill of Rights to state governments.

A legal doctrine that extends the exclusionary rule to evidence derived from an illegal search, arrest, or interrogation. If the initial police action was unconstitutional (the "poisonous tree"), then any evidence obtained as a result (the "fruit") is also inadmissible in court. This doctrine was established in Wong Sun v. United States (1963).

A legal rule that prevents evidence obtained in violation of a defendant's constitutional rights from being used in court. Established in Mapp v. Ohio (1961), the exclusionary rule applies to evidence obtained through illegal searches, coerced confessions, and other constitutional violations. Its purpose is to deter unlawful police conduct.

A body of citizens (typically 16-23 people) convened to evaluate whether there is sufficient evidence to formally charge a person with a crime (issue an indictment). Grand jury proceedings are secret, and the standard is "probable cause" — a lower standard than the "beyond a reasonable doubt" required for conviction at trial.

A legal order (Latin for "produce the body") requiring a person under detention to be brought before a court to determine whether the detention is lawful. It is one of the most important safeguards against unlawful imprisonment, enshrined in Article I, Section 9 of the Constitution.

An out-of-court statement offered in court to prove the truth of the matter asserted. Hearsay is generally inadmissible as evidence because the person who made the statement is not available for cross-examination. However, there are numerous exceptions to the hearsay rule, including excited utterances, dying declarations, and business records.

A witness who is antagonistic or uncooperative toward the party that called them. When a judge declares a witness hostile, the calling party is permitted to ask leading questions (typically reserved for cross-examination). This can occur when a witness's testimony contradicts their prior statements.

Protection from legal liability. In law enforcement, there are several forms: absolute immunity (complete protection, typically for judges and prosecutors), qualified immunity (protection for officers unless they violate "clearly established" rights), and sovereign immunity (protection for government entities). Immunity is one of the biggest barriers to police accountability.

A legal doctrine stating that by operating a motor vehicle on public roads, drivers have implicitly agreed to submit to chemical testing (breath, blood, or urine) if lawfully arrested for driving under the influence. Refusing a chemical test after arrest can result in automatic license suspension and other penalties, even if you are not ultimately convicted of DUI.

A formal accusation issued by a grand jury charging a person with a crime. An indictment is required for federal felony prosecutions under the Fifth Amendment. The grand jury must find probable cause that the accused committed the crime before issuing an indictment.

A person who provides information to law enforcement about criminal activity, often in exchange for leniency on their own charges, financial compensation, or other benefits. Informant tips can establish probable cause for warrants and arrests, but courts require corroboration of informant information due to reliability concerns.

A court order requiring a person or entity to do or refrain from doing a specific act. Injunctions can be temporary (restraining orders) or permanent. Violating an injunction can result in contempt of court charges.

The formal questioning of a suspect by law enforcement. Under Miranda v. Arizona, officers must advise suspects of their rights before custodial interrogation. Interrogation includes not only direct questioning but also any words or actions by police that are reasonably likely to elicit an incriminating response.

A warrantless search of a lawfully impounded vehicle conducted to catalog its contents. The purpose is to protect the owner's property, protect police from claims of theft, and ensure safety. Inventory searches must follow standardized department procedures and cannot be used as a pretext to search for evidence.

The official power of a court or legal body to make legal decisions and judgments. Jurisdiction also refers to the geographic area or subject matter over which a court or law enforcement agency has authority. Laws vary by jurisdiction, which is why knowing your state and local laws is essential.

A specialized law enforcement unit that uses trained police dogs for detection (drugs, explosives), tracking suspects, and apprehension. The Supreme Court ruled in Rodriguez v. United States (2015) that police cannot extend a traffic stop beyond its original purpose to conduct a dog sniff without reasonable suspicion.

An attorney or lawyer who provides legal advice and representation. Under the Sixth Amendment, every person accused of a crime has the right to legal counsel. If you cannot afford an attorney, one must be appointed to you free of charge (a public defender). The right to counsel attaches at all critical stages of criminal proceedings.

A procedure in which a witness or victim views a group of people (or photographs) to identify the person who committed the crime. Lineups can be conducted live (in person) or through photo arrays. The Sixth Amendment guarantees the right to have an attorney present at post-indictment lineups.

A judicial officer with limited authority, typically responsible for issuing warrants, setting bail, conducting preliminary hearings, and handling minor offenses. Magistrates serve as a check on law enforcement by requiring officers to demonstrate probable cause before warrants are issued.

The rights that law enforcement must inform suspects of before custodial interrogation, established by Miranda v. Arizona (1966). These include: the right to remain silent, that anything said can be used against you in court, the right to an attorney, and that an attorney will be provided if you cannot afford one. Failure to give Miranda warnings makes resulting statements inadmissible.

A criminal offense less serious than a felony, typically punishable by fines, probation, community service, or imprisonment for up to one year in a local jail (not state prison). Common misdemeanors include minor theft, simple assault, trespassing, disorderly conduct, and first-offense DUI in many states.

A formal request to the court to exclude certain evidence from trial because it was obtained in violation of the defendant's constitutional rights. Common grounds include illegal searches (Fourth Amendment), coerced confessions (Fifth Amendment), and violations of the right to counsel (Sixth Amendment).

A warrant that authorizes law enforcement to enter a premises without first knocking and announcing their presence. No-knock warrants are issued when officers demonstrate to a judge that announcing their presence would result in the destruction of evidence, the escape of suspects, or danger to officers. These warrants have been the subject of significant controversy and reform.

Latin for "I do not wish to contend." A plea in which the defendant does not admit guilt but accepts punishment as if guilty. Unlike a guilty plea, a nolo contendere plea generally cannot be used as an admission of guilt in a subsequent civil lawsuit, making it strategically advantageous in some cases.

A recording law that allows a person to record a conversation as long as at least one party to the conversation consents. In one-party consent states, you can legally record your own conversations — including interactions with police — without informing the other party. The majority of U.S. states follow one-party consent rules.

Laws that prohibit the possession of open containers of alcohol in public places or in the passenger area of a motor vehicle. Most states have open container laws that apply to both drivers and passengers. A visible open container can give officers probable cause or reasonable suspicion to investigate further.

The supervised release of a prisoner before the completion of their sentence. Parole is granted by a parole board and comes with conditions that the parolee must follow. Violating parole conditions can result in being sent back to prison to serve the remainder of the original sentence.

A limited search of a person's outer clothing, conducted by running hands over the body to detect weapons. Also called a "frisk," a pat-down is permitted during a Terry stop when an officer has reasonable suspicion that the person is armed and dangerous. The pat-down is limited to checking for weapons, not other contraband.

A negotiated agreement between the prosecution and defense in which the defendant pleads guilty to a lesser charge or receives a reduced sentence in exchange for avoiding a trial. Approximately 90-95% of criminal cases in the United States are resolved through plea bargains rather than going to trial.

The common expression for invoking the Fifth Amendment right against self-incrimination. A person "pleads the Fifth" when they refuse to answer questions because their answers might incriminate them. This right can be invoked during police questioning, grand jury testimony, and at trial.

The use of excessive and unnecessary force by law enforcement against civilians. Police brutality can include physical violence, verbal abuse, intimidation, and the use of weapons or restraints beyond what is reasonably necessary. It violates the Fourth Amendment's protection against unreasonable seizures and the Fourteenth Amendment's due process protections.

Any inappropriate or illegal action taken by police officers in connection with their duties. This includes excessive force, false arrest, racial profiling, evidence tampering, perjury, sexual misconduct, and corruption. Police misconduct violates both departmental policies and constitutional rights.

A court proceeding held before trial to determine whether there is sufficient evidence (probable cause) to require a trial. At a preliminary hearing, the prosecution must present enough evidence to convince the judge that a crime was committed and the defendant likely committed it. The defense can cross-examine witnesses and challenge evidence.

A reasonable basis for believing that a crime has been, is being, or will be committed. Probable cause is required under the Fourth Amendment for arrests, searches, and issuing warrants. It is a higher standard than reasonable suspicion but lower than the "beyond a reasonable doubt" standard needed for conviction.

A court-ordered period of supervision in the community as an alternative to incarceration. Probation conditions may include regular check-ins with a probation officer, drug testing, community service, and restrictions on travel. Violating probation conditions can result in the imposition of the original jail or prison sentence.

The authority of a prosecutor to decide whether to bring criminal charges, what charges to file, whether to offer a plea bargain, and how to allocate resources. Prosecutors have broad discretion in making these decisions, and their choices significantly impact the outcome of criminal cases.

A lawyer appointed by the court to represent defendants who cannot afford to hire private counsel. The right to a public defender is guaranteed by the Sixth Amendment as interpreted in Gideon v. Wainwright (1963). Public defenders handle a wide range of criminal cases and are licensed attorneys with the same qualifications as private attorneys.

A judicial doctrine that protects government officials, including police officers, from civil liability unless their conduct violates "clearly established" statutory or constitutional rights that a reasonable person would have known. Created by the Supreme Court, qualified immunity has become one of the most significant barriers to holding officers accountable for misconduct.

A legal standard lower than probable cause, requiring specific and articulable facts that would lead a reasonable person to suspect criminal activity. Reasonable suspicion is sufficient for a Terry stop (brief investigative detention) and a pat-down for weapons, but not sufficient for a full search or arrest.

Your constitutional right, protected by the First Amendment, to record police officers performing their duties in public spaces. Multiple federal circuit courts have affirmed this right. Officers cannot order you to stop recording, delete footage, or seize your recording device without a warrant. However, you must not physically interfere with police operations while recording.

A criminal charge for physically opposing or obstructing an officer's attempt to make an arrest. Resisting arrest can be charged even if the underlying arrest was unlawful in many jurisdictions. The charge can range from a misdemeanor to a felony depending on the level of resistance and whether any injuries occurred.

The Sixth Amendment right to have an attorney represent you in criminal proceedings. This right attaches at all critical stages of prosecution, including arraignment, preliminary hearings, trial, and sentencing. If you cannot afford an attorney, one must be appointed to you free of charge.

The Fifth Amendment right to refuse to answer questions or provide information that could be used against you in a criminal prosecution. This right applies during police encounters, custodial interrogation, grand jury proceedings, and at trial. You must explicitly invoke this right for it to take effect.

A term derived from Rodriguez v. United States (2015), where the Supreme Court held that a traffic stop cannot be prolonged beyond the time needed to complete the stop's original purpose — even for a brief dog sniff — without reasonable suspicion of additional criminal activity. This limits how long officers can detain you during a routine stop.

The legal process by which law enforcement examines a person's property or person (search) and takes possession of items as evidence (seizure). The Fourth Amendment requires that searches and seizures be "reasonable" and generally requires a warrant based on probable cause. Exceptions include consent searches, searches incident to arrest, and exigent circumstances.

A court order authorizing law enforcement to search a specific location for specific items related to a crime. A valid search warrant must be based on probable cause, supported by an affidavit, issued by a neutral magistrate, and describe the place to be searched and items to be seized with particularity.

A federal statute (42 U.S.C. § 1983) that allows individuals to sue state and local government officials — including police officers — for violations of their constitutional rights. Originally part of the Civil Rights Act of 1871, Section 1983 is the primary vehicle for civil rights lawsuits against law enforcement.

The act of providing testimony or evidence that implicates oneself in criminal activity. The Fifth Amendment protects against compelled self-incrimination, meaning the government cannot force you to testify against yourself. This protection applies to any government proceeding, including police interrogation, grand jury testimony, and trial.

The Sixth Amendment guarantees the rights of criminal defendants, including the right to a speedy and public trial, an impartial jury, to be informed of charges, to confront witnesses, to compulsory process for obtaining witnesses, and to the assistance of counsel. These protections apply at all critical stages of prosecution.

A self-defense law that allows individuals to use force (including deadly force in some states) to defend themselves without a duty to retreat, as long as they are in a place where they have a legal right to be and reasonably believe force is necessary to prevent death or serious bodily harm. Approximately 30 states have some form of stand your ground law.

A law enforcement practice allowing officers to briefly stop, question, and pat down individuals based on reasonable suspicion of criminal activity. Authorized by Terry v. Ohio (1968), the practice has been controversial due to concerns about racial profiling and civil rights violations. The frisk is limited to checking for weapons.

State laws that require a person to identify themselves to law enforcement when stopped and asked. Approximately 24 states have stop-and-identify statutes. These laws were upheld by the Supreme Court in Hiibel v. Sixth Judicial District Court (2004). Requirements vary — some states only require you to state your name, while others require you to produce identification.

A legal document ordering a person to appear in court to testify (subpoena ad testificandum) or to produce documents or evidence (subpoena duces tecum). Failure to comply with a subpoena can result in contempt of court charges. Both the prosecution and defense can issue subpoenas.

A pre-trial hearing where the court determines whether certain evidence should be excluded from trial because it was obtained in violation of the defendant's constitutional rights. The defense files a motion to suppress, and the prosecution must prove the evidence was lawfully obtained. If the motion is granted, the evidence cannot be used at trial.

A brief investigative detention by police based on reasonable suspicion of criminal activity, named after Terry v. Ohio (1968). During a Terry stop, officers may briefly question the person and, if they have reasonable suspicion the person is armed, conduct a pat-down for weapons. The stop must be brief and limited in scope.

A formal statement given under oath by a witness in a legal proceeding. Testimony can be given at trial, depositions, hearings, or before a grand jury. False testimony given under oath constitutes perjury, which is a criminal offense. Witnesses can be examined, cross-examined, and impeached based on their testimony.

A recording law requiring all parties to a conversation to consent before it can be legally recorded. Approximately 11 states are two-party (or all-party) consent states: California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, New Hampshire, Pennsylvania, and Washington. Recording without all-party consent in these states may be a crime.

Holding a person in custody without legal justification. Unlawful detention occurs when police detain someone without reasonable suspicion (for a stop) or probable cause (for an arrest), or extend a lawful detention beyond a reasonable time. It violates the Fourth Amendment's protection against unreasonable seizures.

The amount of physical effort required by police to compel compliance from an unwilling subject. Use of force policies govern when and how much force officers may use. The Supreme Court's "objective reasonableness" standard (Graham v. Connor) evaluates use of force from the perspective of a reasonable officer on the scene, not with 20/20 hindsight.

The formal decision or finding made by a jury or judge on the matters submitted for their judgment. In criminal cases, the verdict is either guilty or not guilty. A unanimous verdict is required for federal criminal cases and in most states. If the jury cannot reach a unanimous verdict, it results in a "hung jury" and a potential mistrial.

The process of questioning prospective jurors to determine their suitability for jury service. During voir dire, attorneys for both sides can challenge potential jurors "for cause" (demonstrable bias) or use peremptory challenges (no reason required, but cannot be based on race or gender per Batson v. Kentucky). The goal is to select an impartial jury.

A written order issued by a judge or magistrate authorizing law enforcement to take a specific action, such as making an arrest (arrest warrant) or conducting a search (search warrant). The Fourth Amendment requires that warrants be based on probable cause, supported by oath or affirmation, and particularly describe the place to be searched or person to be seized.

A search conducted by law enforcement without first obtaining a search warrant. While the Fourth Amendment generally requires warrants, courts have recognized several exceptions: consent searches, searches incident to arrest, the automobile exception, plain view doctrine, exigent circumstances, Terry frisks, and inventory searches.

A person who has knowledge relevant to a legal proceeding and provides testimony under oath. Witnesses can be eyewitnesses (who observed events), expert witnesses (who provide specialized knowledge), or character witnesses (who speak to a person's character). The Sixth Amendment guarantees the right to confront witnesses and to compel witness testimony.

An arrest made without probable cause or legal authority, or an arrest based on mistaken identity or false information. Wrongful arrest can form the basis of both criminal charges against the officer and civil liability under Section 1983. Victims of wrongful arrest may recover compensatory and punitive damages.