Glossary
Definitions of legal, medical, statistical, and tactical terms used in EWRL research.
- Active Resistance
- Physical evasive actions where a subject actively pulls away, flees, pushes, or braces against an officer to prevent control or custody, without launching a direct physical assault on the officer.
- Actus Reus
- The physical, observable act or conduct that constitutes the unlawful element of a crime, distinct from the actor's mental state.
- Aggravated Flight (Armed Evasion)
- The act of fleeing or eluding law enforcement while actively possessing, displaying, or manipulating a deadly weapon, significantly elevating the risk environment.
- Ammunition
- A complete assembly consisting of a projectile, cartridge case, propellant powder, and primer used in firearms.
- Armored Vehicle
- A ballistically armored police vehicle — such as a Lenco BearCat or MRAP — deployed to provide hard cover or mobile containment at an incident scene.
- Full explainer →
- Assaultive
- Active physical engagement where a subject attempts to cause, or successfully inflicts, bodily harm upon an officer or civilian using physical force, a weapon, or a vehicle instrument.
- Ballistics
- The scientific study of the motion, behavior, and effects of projectiles, particularly bullets and gravity-bombs, from the moment they are fired until they impact a target.
- Baton
- A handheld impact weapon used to deliver strikes or apply mechanical control. Includes collapsible batons, nightsticks, PR-24s, and ASPs.
- Full explainer →
- Brandishing
- The act of overtly displaying, waving, holding, or manipulating a weapon in a visible manner that signals its presence and availability, but falls short of a direct physical attack.
- Conducted Energy Weapon / Taser
- A weapon that delivers a brief electrical current to temporarily disrupt voluntary muscle control. Classified as less-lethal and intended to stop active resistance without lethal injury.
- Full explainer →
- Coroner
- An elected or appointed public official who investigates the cause, manner, and circumstances of sudden, unexplained, or violent deaths.
- Crisis / Hostage Negotiator
- A certified law enforcement negotiator physically on-scene before lethal force was deployed. Distinct from patrol officers who attempted to communicate with a subject.
- Full explainer →
- Crisis Intervention Team
- A law enforcement officer or unit with a dedicated, regular assignment to mental health crisis response — distinct from patrol officers who have completed standard CIT academy training.
- Full explainer →
- Culpable
- A legal status indicating that a person's conduct is blameworthy, reckless, or criminally negligent, carrying legal responsibility for a harmful outcome.
- Eluding
- Evasive actions, concealment, or deceptive maneuvers designed by a subject to break visual contact, avoid detection, or slip away from law enforcement tracking.
- Entry Wound
- The initial site where a projectile or weapon pierces and breaches the exterior skin surface of the body.
- Excusable Homicide
- A killing committed accidentally or through a misadventure during a lawful act, where the actor bore no criminal intent or culpable negligence.
- Exigent Circumstances
- Critical emergency situations such as immediate threats to life, hot pursuit of a suspect, or imminent destruction of evidence that legally justify law enforcement taking immediate action without a prior warrant.
- Exit Wound
- The injury produced when a projectile exits the body, typically characterized by larger, more irregular, and lacerated edges than an entry site.
- Exsanguination
- Severe, fatal blood loss resulting from massive internal or external hemorrhaging caused by major vascular or organ trauma.
- Extended-Range Chemical Weapon
- A launcher-fired projectile that delivers a chemical irritant payload at range. Common platforms include the PepperBall launcher and FN 303.
- Full explainer →
- Extended-Range Impact Weapon
- A dedicated launcher — typically 37mm, 40mm, or ARWEN — that fires blunt-force kinetic projectiles such as sponge rounds, rubber baton rounds, or foam-tipped rounds.
- Full explainer →
- Fleeing
- The active creation of physical distance by a subject on foot or in a vehicle to intentionally escape or avoid immediate detention by law enforcement.
- Homicide
- The killing of one human being by another, which serves as a broad classification encompassing both lawful acts (such as justifiable self-defense) and unlawful acts.
- Imminent Threat
- An immediate, pressing danger that is actively unfolding and about to happen at any second, requiring an instantaneous response to prevent death or serious bodily harm.
- Improvised / Atypical Less-Lethal Force
- A non-standard or improvised less-lethal method not captured by other weapon categories — for example, a flashlight used as a strike weapon or a police vehicle used as a force instrument.
- Full explainer →
- Incision
- A clean, linear wound with sharp margins typically produced by a sharp-edged instrument or weapon, where the length of the skin injury exceeds its depth.
- Justifiable Homicide
- The intentional but legally sanctioned killing of a human being, performed in the line of duty by a public officer or in necessary self-defense to prevent a lethal threat.
- Laceration
- A jagged, irregular wound or tear in skin and soft tissue typically caused by blunt- force trauma or tearing, rather than a clean slice.
- Less-Lethal Force
- A derived indicator that captures whether any less-lethal weapon was deployed during an encounter, across eleven individual modalities tracked by the Lab.
- Less-Lethal Shotgun
- A 12-gauge shotgun platform loaded with flexible kinetic munitions — typically beanbag rounds — rather than lethal ammunition.
- Full explainer →
- Manifest Conduct
- The observable, physical actions and verbal statements of a subject used by researchers to analyze threat progression, distinct from unobservable internal intent or motivation.
- Mean
- The mathematical average of a dataset calculated by summing all individual numerical values and dividing by the total count of observations.
- Median
- The exact middle value in a distribution of data when the observations are arranged in sequential order, splitting the dataset into two equal halves.
- Medical Examiner
- A medically trained physician, typically a forensic pathologist, appointed to investigate suspicious deaths and perform autopsies.
- Mens Rea
- The state of mind or criminal intent accompanying an unlawful act, reflecting the degree of knowledge, purpose, or recklessness of the actor.
- Mode
- The specific value or category that appears with the highest frequency within a given dataset or distribution.
- Murder
- The unlawful killing of a human being with malice aforethought or criminal intent, representing a specific legal subcategory of homicide.
- OC Spray
- Oleoresin capsicum (pepper spray) or a similar chemical irritant discharged from a handheld canister directly at a subject.
- Full explainer →
- Passive Resistance
- Non-compliance where a subject refuses to obey lawful commands or physical direction but remains completely non-violent, using only dead weight or stationary physical inertia to prevent control.
- Penetrating Wound
- An injury where a projectile or weapon enters an organ, cavity, or tissue layer but does not pass completely through to create an exit point.
- Perforating Wound
- A through-and-through injury where a projectile or weapon enters a structure or tissue layer, passes completely through it, and exits the other side.
- Permanent Cavity
- The visible, localized path of permanent tissue destruction and crushing left behind along the direct track of a penetrating projectile.
- Pistol
- A semi-automatic handgun or revolver discharged with lethal ammunition. The most common lethal force method in the Lab's dataset.
- Full explainer →
- Police Service Dog
- A trained police dog released to physically engage or apprehend a subject on command.
- Full explainer →
- Possessing
- The state of having a weapon physically on one's person, within immediate reach, or under direct physical control without actively displaying, manipulating, or pointing it.
- Protected Interest
- The primary person or safety interest the officer acted to protect when initiating lethal force — officer safety, a third party, both, or indeterminate where records lack sufficient detail.
- Puncture
- A deep, narrow wound caused by a pointed object such as a needle, nail, or knife tip that penetrates deeply into the body with relatively small surface damage.
- Re-entry Wound
- The secondary entry point produced when a single projectile exits one part of the body (such as an arm) and immediately penetrates another region (such as the torso).
- Reliability
- The consistency and stability of a measurement method or coding instrument when applied repeatedly to the same cases under identical conditions.
- Remote Restraint Device / BolaWrap
- A projectile-launched tether or net system — such as the BolaWrap — designed to remotely entangle a subject's limbs or torso from a distance.
- Full explainer →
- Rifle
- A shoulder-fired, rifled long gun discharged with lethal ammunition. Includes patrol rifles, carbines, and tactical sniper platforms.
- Full explainer →
- Riot / Ballistic Shield
- A polycarbonate riot shield or handheld ballistic shield actively carried and used on- scene for officer or civilian protection.
- Full explainer →
- Shield Law (Marsy's Law)
- A constitutional amendment or statutory provision designed to protect the rights, privacy, and safety of crime victims, which is frequently cited in post-incident police reports to withhold the identities of involved individuals.
- Shotgun — Lethal
- A smoothbore shotgun discharged with lethal ammunition — buckshot or slugs. Distinct from the less-lethal shotgun, which fires beanbag rounds.
- Full explainer →
- Stab Wound
- A penetrating wound produced by a sharp or pointed weapon where the depth of the internal injury track is greater than the length of the skin breach.
- Statistical Significance
- A calculation indicating that an observed relationship, pattern, or difference within a dataset is highly unlikely to have occurred purely by random chance.
- Tactical Unit / SWAT
- A designated special weapons and tactics team (SWAT, ERT, HRT, ESU) formally activated and physically on-scene. Excludes standard investigative units without tier-1 tactical capability.
- Full explainer →
- Tear Gas
- CS or CN gas canisters or grenades deployed for environmental area saturation — intended to deny or clear a space rather than target an individual.
- Full explainer →
- Temporary Cavity
- The brief, dynamic stretching of surrounding tissue away from a projectile's path caused by the transfer of kinetic energy during impact.
- Threatening
- Conduct consisting of verbal statements, gestures, or physical posturing that communicates an explicit, immediate intent to inflict physical injury or death upon another person.
- Unmanned Aerial System / Drone
- A remotely piloted aircraft deployed by law enforcement for reconnaissance, situational awareness, or tactical support during an incident.
- Full explainer →
- Unmanned Ground Vehicle / Robot
- A remotely operated ground robot deployed by law enforcement for reconnaissance, EOD tasks, or tactical support.
- Full explainer →
- Validity
- The degree to which a variable, metric, or study design accurately measures the specific concept it intends to capture rather than an unintended factor.