Investigative Services key terms

A documented, unbroken record showing who collected, handled, transferred, and stored an item of evidence, and when, so its identity and integrity can be proven in court.

The assurance that an item has not been altered, substituted, contaminated, or degraded from collection through presentation, typically demonstrated through sealed packaging and complete documentation.

A closure or label designed to show visible damage if opened, allowing anyone to detect unauthorized access to packaged evidence or storage containers.

A running register recording each item's description, identifying number, location found, collector, and every subsequent transfer or movement.

A controlled storage area with restricted access, environmental safeguards, and inventory records where evidence is held pending analysis, trial, or disposition.

The loss, destruction, or material alteration of evidence that undermines its availability or reliability, which can trigger sanctions or adverse inferences in litigation.

A directive requiring an organization to preserve documents and data potentially relevant to anticipated or active litigation or investigation, suspending routine deletion.

The process of identifying, preserving, collecting, reviewing, and producing electronically stored information in response to litigation or regulatory demands.

Creating a bit-for-bit duplicate of a storage device or data set while preserving original content, often verified by comparing hash values of source and copy.

A fixed-length digital fingerprint computed from file or device contents; any change to the data produces a different value, supporting verification of authenticity.

A hardware or software tool that permits read access to a storage device while preventing any write operation, protecting original data during acquisition.

The forensic concept that contact between two objects results in transfer of material between them, meaning perpetrators often leave and carry away trace evidence.

Small quantities of physical material such as hair, fibers, glass, soil, paint, or gunshot residue transferred during contact and used to link people, objects, and places.

Introduction of foreign material or data into evidence that reduces its probative value, often through improper handling, shared tools, or uncontrolled environments.

The degree to which a piece of evidence tends to make a fact of consequence more or less likely, weighed against risks such as unfair prejudice or confusion.

The threshold determination that evidence may be considered by a court because it satisfies rules on relevance, authenticity, reliability, and lawful acquisition.

The quality of evidence that has a tendency to make a material fact more or less probable than it would be without the evidence.

An out-of-court statement offered to prove the truth of the matter asserted, generally inadmissible unless an exception or exclusion applies.

In United States practice, notice given before custodial interrogation advising a suspect of rights to remain silent, to counsel, and to appointed counsel if indigent.

Questioning by law enforcement after a person has been taken into custody or otherwise deprived of freedom in a significant way, triggering protective procedural safeguards.

The requirement that a statement be the product of free choice rather than coercion, threats, promises, deception, or exhaustion, or it may be excluded.

A knowing, intelligent, and voluntary relinquishment of a right, such as the right to silence or counsel, often documented in writing or recorded on audio or video.

An interview or interrogation method that overbears a subject's will through threats, physical deprivation, promises of leniency, or prolonged questioning, risking statement suppression.

An admission to a crime a person did not commit, arising from factors such as coercion, fatigue, suggestibility, youth, cognitive impairment, or misunderstanding of consequences.

A structured, non-accusatory method that uses memory-retrieval techniques such as context reinstatement and varied recall order to improve witness accuracy.

A contemporaneous written, audio, or video account of a subject's statements, capturing questions asked, answers given, timing, and any breaks or interruptions.

A procedure in which a witness selects a suspect from a lineup, photo array, or show-up; reliability depends on estimator and system variables and proper procedure.

Systematic observation of people, places, or activities to gather information, conducted overtly or covertly and subject to legal limits on privacy intrusion.

An activity conducted so that the subject is unaware of the investigator's identity or purpose, often requiring authorization, cover arrangements, and careful documentation.

A detailed chronological record of observations during surveillance, including times, locations, subjects, actions, and any gaps in coverage.

Inducement by government agents of a person to commit a crime they were not predisposed to commit, providing a defense in many jurisdictions.

An inquiry in which an investigator assumes a false identity or role to obtain information from targets who do not know they are dealing with an investigator.

A judicial authorization permitting a specified action such as search, seizure, arrest, or electronic monitoring, typically requiring probable cause and particularity.

A reasonable belief, based on facts and circumstances, that a crime has occurred or that evidence will be found in a particular place.

A model explaining occupational fraud through three conditions: pressure or incentive, opportunity, and rationalization, each of which can be assessed during investigation.

An indicator or anomaly, such as unusual transactions, lifestyle changes, or control weaknesses, suggesting possible fraud or misconduct warranting further inquiry.

Following the movement of money or property through accounts, entities, and transactions to identify proceeds, beneficiaries, and recoverable assets.

The identity of the natural persons who ultimately own or control a legal entity or account, regardless of nominal title holders.

A filing made by regulated financial institutions to a financial intelligence unit describing transactions that may indicate money laundering, fraud, or other criminal activity.

The planning, tracking, and coordination of investigative tasks, resources, deadlines, and documentation from intake through closure and review.

A written strategy stating the allegation, objectives, scope, hypotheses, required evidence, resources, timeline, and legal constraints before fieldwork begins.

The organized collection of reports, evidence records, correspondence, and analysis documenting an investigation and supporting review, disclosure, and testimony.

A structured evaluation of the likelihood and impact of harm to people, operations, or evidence, used to select proportionate safety and security controls.

Pre-arranged measures such as communication checks, backup support, site reconnaissance, and extraction routes that protect investigators during field activity.

A situation in which an investigator's personal, financial, or professional interests could improperly influence judgment, requiring disclosure, recusal, or other safeguards.

Freedom from influence or control by parties with a stake in the outcome, allowing investigators to reach conclusions based solely on evidence.

An administrative separation preventing information or personnel from crossing between teams, used to manage conflicts and protect confidentiality.

Information that tends to negate guilt, mitigate an offense, or impeach a prosecution witness, which may need to be disclosed to the defense.

Questioning of a witness by the party who called them, generally using open questions to elicit a clear, complete, and credible account.

Questioning of a witness by the opposing party, typically using leading questions to test accuracy, bias, perception, and consistency of the account.

Reviewing reports, exhibits, and prior statements and rehearsing clear answers so a witness can present accurate, consistent evidence under questioning.