MO POST key terms

A reasonable belief, based on facts and circumstances an officer can articulate, that a crime has been, is being, or will be committed, or that evidence of a crime will be found in a particular place.

A standard lower than probable cause that permits a brief detention when specific, articulable facts and rational inferences suggest criminal activity is occurring or about to occur.

A brief investigative detention based on reasonable suspicion, during which an officer may identify the person, ask questions, and pat down outer clothing if a weapon is suspected; from Terry v. Ohio.

The advisement required before custodial interrogation: the right to remain silent, that statements may be used against the suspect, and the right to an attorney including appointed counsel.

Urgent conditions that justify acting without a warrant, such as hot pursuit, imminent destruction of evidence, or an immediate threat to the safety of officers or others.

The person who poses the greatest threat of continuing violence in a domestic disturbance; identifying that person helps officers avoid arresting a victim who acted in self-defense.

A philosophy pairing officers with residents to identify and solve the conditions that produce crime, emphasizing partnership, communication, and prevention alongside enforcement.

A four-step problem-solving method - scanning, analysis, response, assessment - that patrol officers use to address recurring problems instead of repeatedly handling the same symptoms.

Be-on-the-lookout: a broadcast describing a wanted person, vehicle, or stolen property so patrol officers can locate and identify it; specific, accurate identifiers make the broadcast useful.

The documented, unbroken record of every person who handled a piece of evidence, and when and where; gaps cast doubt on authenticity and can make the item inadmissible.

An out-of-court statement offered to prove the truth of what it asserts; generally inadmissible at trial unless a recognized exception applies, such as an excited utterance.

The doctrine that evidence obtained through an unconstitutional search or seizure is generally inadmissible against the person whose rights were violated; limited by exceptions such as inevitable discovery.

A one-on-one identification of a detained suspect near the scene soon after a crime; inherently suggestive, so officers should minimize cues and document exactly what was said and done.

The validated battery - horizontal gaze nystagmus, walk-and-turn, and one-leg stand - administered in the prescribed manner to detect impairment and support an impaired-driving arrest.

Involuntary jerking of the eye as it tracks a stimulus; scoring considers onset before 45 degrees, distinct jerking at maximum deviation, and jerking within four seconds.

The principle that a driver lawfully arrested for an alcohol- or drug-related offense has already consented to chemical testing, and refusal carries license consequences rather than forced testing.

A reconstruction calculation using drag factor and skid distance to estimate the minimum speed a vehicle was traveling when braking began; the result is a minimum, not a precise speed.

The Fourth Amendment test for force: whether a reasonable officer, facing the same facts and without hindsight, would consider the force proportionate and necessary; from Graham v. Connor.

Every fact known to the officer when force was used - the subject's behavior, threats, numbers, environment, and the officer's own actions - weighed together rather than separately.

The obligation to stop and report another officer's clearly excessive force when there is a realistic opportunity, regardless of rank or agency; failure can bring discipline and liability.

Using time, distance, cover, tactical repositioning, and communication to reduce the likelihood that force is needed when it is safe and feasible to do so.

Impaired breathing caused by body position, commonly after prolonged prone restraint or weight on the back; officers should move restrained subjects to a seated or side-recovery position and monitor breathing.

Cover stops projectiles; concealment only hides you from view. Choosing positions that actually defeat the ammunition involved is a basic decision in any armed encounter.

Immediate action to clear a firearm stoppage, typically tap the magazine, rack the slide, and reassess; practiced until automatic so it can be performed under stress.

Treat every firearm as loaded, never point it at anything you are unwilling to destroy, keep your finger off the trigger until ready to fire, and know your target and what lies beyond.

The statutory duty of an emergency driver to drive with care for others while using lights and siren; it does not authorize reckless driving or shield the officer from liability.

An active attempt to catch a fleeing vehicle; supervisors and officers must weigh the danger created by the pursuit against the need for immediate apprehension and apply agency policy.

Slowing and visually confirming that cross traffic has stopped or yielded before entering an intersection against a signal or sign during an emergency response.

The specific facts the state must prove for a given charge; a report written to address each element gives the prosecutor a case instead of a story.

Recording observable facts, exact statements, times, and descriptions rather than opinions or conclusions, so the account can be verified and withstands cross-examination.

A follow-up report adding information learned after the original, such as later interviews or lab results; it supplements but never alters or replaces the original record.

The finding that people more readily accept police authority when they perceive the process as fair, transparent, and respectful, even when the outcome is unfavorable to them.

An informal norm of not reporting a colleague's misconduct; it protects wrongdoing, exposes officers and agencies to liability, and erodes the public trust policing depends on.

A gift, discount, or favor accepted because of one's official position; even small gratuities can create obligation or the appearance of corruption and are often banned by policy.

A constricting band placed above a life-threatening limb bleed; tighten until hemorrhage stops, record the application time, and leave it in place until medical personnel take over.

Chest compressions, with or without rescue breaths, that circulate oxygenated blood when a person is unresponsive and not breathing normally; continue until an AED or medics arrive.

Treating all blood and body fluids as potentially infectious by using gloves, eye protection, and hand hygiene, regardless of what is known about the person.

The physical and emotional reaction that can follow a shooting, fatal crash, or death notification; recognized early, it responds to peer support and professional debriefing rather than isolation.