DC POST key terms

The facts and circumstances known to an officer that would lead a reasonable person to believe a crime has been, is being, or will be committed, or that evidence of a crime exists in a particular place.

A lower standard than probable cause in which specific, articulable facts, taken with rational inferences, suggest criminal activity is afoot, justifying a brief investigative stop.

A brief detention of a person based on reasonable suspicion of criminal activity, permitting limited questioning and, where officer safety requires, a pat-down of outer clothing for weapons.

An investigative detention paired with a limited pat-down of a person's outer clothing for weapons, allowed only when the officer reasonably suspects the person is armed and dangerous.

A judicial order supported by sworn probable cause that authorizes officers to take a named person into custody, typically for a felony or a misdemeanor not committed in the officer's presence.

A court order, based on sworn probable cause, authorizing officers to search a specified place or person and seize described items within a defined scope and time frame.

The doctrine barring the government from introducing at trial evidence obtained in violation of a defendant's constitutional rights, subject to recognized exceptions such as inevitable discovery and good faith.

The rule that evidence derived from an unconstitutional search or seizure is also inadmissible, unless the link is broken by an independent source, inevitable discovery, or attenuation.

The advisement of the right to remain silent, that statements may be used against the speaker, the right to counsel, and appointed counsel for indigent defendants, required before custodial interrogation.

Questioning by law enforcement after a person has been taken into custody or otherwise deprived of freedom in a significant way, triggering the requirement for Miranda warnings.

The requirement that a suspect's statement be the product of free and rational choice, not coercion, threats, promises, or exhaustion, regardless of whether warnings were given.

The constitutional guarantee of fair procedures and fundamental fairness in government action, including notice, a hearing, and protection from arbitrary deprivation of life, liberty, or property.

The constitutional principle requiring government to treat similarly situated persons alike, prohibiting discrimination on grounds such as race, sex, religion, or national origin absent sufficient justification.

The constitutional provision protecting people against unreasonable searches and seizures and requiring warrants to be supported by probable cause, particularly describing the place and items.

The constitutional provision guaranteeing grand jury indictment, protection against double jeopardy and self-incrimination, due process, and just compensation for takings.

The constitutional provision guaranteeing the right to a speedy and public trial, an impartial jury, notice of charges, confrontation of witnesses, and assistance of counsel.

The prosecution's constitutional duty to disclose material exculpatory evidence to the defense, including evidence impeaching government witnesses, before trial.

The documented, unbroken chronological record of who handled evidence, when, and for what purpose, from collection through final disposition, used to establish integrity and authenticity.

The proper sealing, labeling, and container selection for collected items so that contamination, loss, and tampering are prevented and the item's condition is preserved for court.

Samples such as blood, saliva, hair, or other tissue containing DNA, which require drying, breathable packaging, refrigeration where appropriate, and strict contamination controls.

The introduction, transfer, or degradation of trace material at a scene by responders, victims, or others, which can undermine forensic value and must be minimized and documented.

The constitutional standard for evaluating force under the Fourth Amendment, judged from the perspective of a reasonable officer on scene, considering the totality of circumstances rather than hindsight.

The three considerations courts weigh in force cases: the severity of the crime at issue, whether the suspect poses an immediate threat, and whether the suspect is actively resisting or evading arrest.

The full set of facts known to an officer at the moment of decision, including subject behavior, environment, numbers, and available resources, evaluated together rather than in isolation.

A framework describing escalating levels of subject resistance and matching officer responses, from presence and verbal direction through control holds, intermediate weapons, and deadly force.

Force that is reasonably likely to cause death or serious bodily injury, permitted only when an officer reasonably believes it is necessary to prevent imminent death or serious injury to self or others.

Techniques such as time, distance, cover, communication, and tactical repositioning used to reduce tension and the likelihood of force when feasible and safe.

The obligation of an officer to stop another officer's clearly excessive force when in a position to do so, and to report the conduct through the chain of command.

A trained approach to interacting with persons in behavioral health crisis that emphasizes communication, recognition of symptoms, time, and referral to appropriate services over arrest where possible.

A philosophy in which officers build ongoing partnerships with residents and address underlying conditions of crime through problem solving, information sharing, and visible engagement.

A structured method in which officers identify recurring problems, analyze their causes, implement tailored responses, and assess results, often summarized by the SARA model.

An analytic model holding that crime requires an offender, a target or victim, and a place or opportunity, so removing any element can prevent the offense.

Reducing crime by altering the environment to increase effort, increase risk, reduce rewards, and remove excuses, such as lighting, access control, and target hardening.

The practice of making enforcement decisions based on behavior and articulable facts rather than race, ethnicity, religion, gender, or other protected characteristics.

Selecting or treating a person differently for stops, searches, or enforcement based on race, ethnicity, or national origin rather than individualized suspicion or behavior.

Specific, observable details an officer can state clearly and support with evidence, as opposed to hunches or unsupported conclusions, forming the basis for reasonable suspicion.

The documented account of an officer's observations, actions, and decisions, written in objective, factual, chronological language that supports prosecution and withstands courtroom scrutiny.

Operating a motor vehicle while affected by alcohol, drugs, or a combination, established through driving behavior, personal contact observations, field sobriety tests, and chemical testing.

Standardized roadside assessments such as horizontal gaze nystagmus, walk-and-turn, and one-leg stand, administered to develop evidence of impairment and probable cause for chemical testing.

The statutory principle that a licensed driver has already agreed to chemical testing when lawfully arrested for impaired driving, subject to refusal consequences defined by state law.

The formal legal process by which one jurisdiction surrenders a person accused or convicted of a crime to another jurisdiction with authority to prosecute or punish.

A program that routes eligible offenders away from prosecution toward treatment, education, or supervision, often used for first-time or behavioral-health-related offenses.

A knowing, intelligent, and voluntary relinquishment of a constitutional right, such as the right to remain silent or to counsel, which must be established by the circumstances.

Trained physical skills for controlling, restraining, and protecting against a subject, emphasizing balance, positioning, control holds, and proportionality to the resistance encountered.