Gun Detection Systems: 3 Technologies Compared (2026)

A gun detection system is any technology that finds a firearm before or as it becomes a threat — and the term covers three completely different technologies that solve three different problems: entry screening finds concealed weapons on people walking in, AI video detection spots a drawn gun on camera, and acoustic gunshot detection locates shots already fired. Most buyers researching “gun detection” are actually choosing between these layers — this guide explains what each does, what each costs, and which combination fits schools, stadiums, churches, courthouses, and hospitals.

The 3 Gun Detection Technologies

1. Entry Screening — Stops Concealed Weapons at the Door

The only layer that finds a weapon before it enters: walk-through screening at controlled entrances. Two sub-categories compete here. Multi-zone metal detectors — 2M Technology’s walk-through line spans 6 to 90 detection zones, pinpointing where on the body an item sits, at 30–60 people per minute per lane, benchmarked against NIJ Standard 0601.02 from the National Institute of Justice. AI concealed-weapons portals (Evolv, CEIA OPENGATE, Xtract One) trade some certainty for speed with free-flow screening — see our full Evolv alternatives comparison including the FTC’s 2024 action on detection-accuracy claims. If visitors searching “concealed weapons detection alternatives to walk-through metal detectors” brought you here: the honest answer is that every alternative is either an AI portal (subscription, vendor-claimed accuracy) or a staffed X-ray + detector checkpoint — there is no third category that finds concealed weapons.

2. AI Video Gun Detection — Spots a Drawn Weapon on Camera

Platforms like ZeroEyes, Omnilert, and Scylla run computer vision on your existing cameras and alert staff within seconds when a visible, drawn firearm appears in frame. Strengths: covers the whole campus (not just doors), works with cameras you already own, no screening lines. The hard limit: it cannot see a concealed weapon — by the time it alerts, the gun is out. It is a response-acceleration layer, priced as a per-camera SaaS subscription, not a prevention layer.

3. Acoustic Gunshot Detection — Locates Shots Already Fired

Sensor networks that recognize the acoustic signature of gunfire and push location data to responders. Deployed mostly by cities and large campuses, this is the last layer of the stack: it shortens response time after the worst has begun. Valuable in a layered plan; meaningless as the only measure.

Side-by-Side: What Each Layer Actually Does

Technology	Fiends	When	Cost Model	Standard/Validation
Multi-zone walk-through detector	Concealed metal weapons	Before entry	One-time, typically under $10K/lane	NIJ 0601.02 (federal standard)
AI concealed-weapons portal	Concealed weapons (vendor AI)	Before entry	Subscription per lane, multi-year	Vendor claims; FTC scrutiny in 2024
AI video gun detection	Drawn, visible firearms	During incident	SaaS per camera	Vendor claims
Acoustic gunshot detection	Shots fired	After first shot	Per-sensor + subscription	Vendor claims

What Each Venue Actually Deploys

Schools: entry screening at main entrances is the layer with a published standard behind it — see metal detectors for schools including Texas grant funding paths, and federal guidance at SchoolSafety.gov. Districts with large budgets sometimes add AI video as a second layer.

Stadiums and arenas: throughput rules everything — free-flow portals or high-count multi-zone lanes at gates, AI video inside the bowl. Our stadium screening guide covers lane math for 400–700 patrons per lane per hour.

Churches and religious centers: most congregations balance welcome against security — discreet single-lane screening for events, camera analytics otherwise. See religious center security, including grant options.

Courthouses and government buildings: screening is mandatory, so the question is configuration, not whether — the standard stack is X-ray plus walk-through detection, covered in our courthouse checkpoint design guide.

Hospitals: emergency departments increasingly screen 24/7 with detector lanes plus a supervised ADA/stretcher bypass — see healthcare facility screening.

Layering: Why the Question Is “Which Combination,” Not “Which One”

Screening without cameras means you catch weapons at doors but see nothing inside. Video AI without screening means you watch a gun come out with no chance to stop it entering. The mature deployments run screening at controlled entries, video analytics across the facility, and — for large campuses — acoustic sensors as the response accelerant. Budget rule of thumb: the screening layer is capital equipment you buy once; both AI layers are subscriptions you pay forever. Price a 5-year total for every option before comparing.

Gun Detection Systems FAQ