Alarm Verification Methods: Calls, Video and Audio
Why this matters
An unverified burglary alarm tells the police one thing: a sensor tripped. Agencies that have chased years of those signals to find a cleaner who forgot the code have learned to treat them as low priority, and some will not respond without verification at all. Verification is what turns "a sensor tripped" into "someone is in the house," or into "the homeowner is home and it was a mistake" before a car rolls. Each method buys certainty at a different price in time and equipment, and the dealer chooses which one an account gets. That choice decides both how many false dispatches the account racks up and how seriously a real alarm is taken.
The four methods and what each one proves
Enhanced call verification (ECV). The operator calls at least two different numbers before dispatching on a burglary signal, usually the premise and then a responsible party's cell. If someone answers with the passcode and says it is a mistake, the operator cancels. If nobody answers, or someone answers without the passcode, the operator dispatches. ECV proves nothing about an intruder. What it does is filter out user error: the person who tripped the alarm is often the person who answers the phone.
Cross-zoned or sequential confirmation. The panel, or the station's software, treats two separate detectors tripping within a set time as a confirmed alarm. A motion detector in the hall and then the bedroom door contact a minute later is much more likely to be a person moving through the house than one detector catching a draft. Confirmation can be done at the panel (cross zoning, in CP-01 terms; see related: False Alarm Reduction Features in the SIA CP-01 Standard) or by the station flagging a second zone after the first.
Two-way audio. The panel opens a voice channel to the station after an alarm. The operator can listen to the premise and speak into it. A voice that answers with the passcode can cancel; breaking glass, shouting or a voice that will not identify itself is information the operator can pass to the agency. Audio depends on a panel and communicator built for it and on the station supporting it.
Video verification. A camera covering the alarmed area sends a short clip or a live view with the alarm. The operator looks before calling. A person on camera who should not be there is a crime in progress, and the operator says so on the dispatch call. Nothing on camera, or the family dog, sends the operator to the call list instead.
What separates them is what reaches the operator's screen. Calls give a human answer or silence. Confirmation gives a pattern. Audio gives sound. Video gives a picture. Only audio and video can show that the alarm is real rather than only that nobody cancelled it.
What each costs in time
Every verification step sits between the signal arriving and the dispatch call. The rest of that path, from the panel's own delays to the agency's queue, is laid out in How a Central Station Handles a Signal, from Panel to Dispatch.
- ECV adds the length of the calls. Two calls that ring out take minutes, not seconds, and that time is spent on every burglary signal on the account, real or false. A good call list (correct numbers, people who actually answer) is what keeps this short.
- Confirmation adds the wait for the second zone. If the second trip comes, it comes quickly. If an intruder trips one zone and stops, a confirmation rule at the panel can mean no report at all. At the station, a single-zone alarm still gets handled; it is just not treated as confirmed.
- Audio adds the listen. Usually short, and it can replace a call to the premise.
- Video adds the look. Seconds to review a clip, if the clip arrives with the alarm and the camera shows the zone that tripped. A camera aimed at the driveway while the alarm is on the back slider shows nothing useful and the operator falls back to calls.
The trade looks like it slows things down, and for the signal-to-dispatch interval it does. But the interval that matters to the customer ends when an officer arrives, and that depends on the priority the agency gives the call.
Why police treat verified alarms differently
Agencies set their own policies, and policies vary by jurisdiction. The common patterns:
- Priority for verified alarms. Some agencies treat a video- or audio-verified burglary as a crime in progress and respond at a higher priority than an unverified alarm. An operator reporting "male subject on camera at the rear door" gets a different response from "burglary alarm, rear door, no answer at premise."
- ECV required before dispatch. Many localities, and some states, require burglary signals to be verified with at least two calls before the station requests dispatch. Fire, medical and panic or hold-up signals are commonly excluded. Where this is law, an operator who skips it may expose the station or the dealer to the penalty the ordinance sets.
- Verified response. A small number of agencies will not respond to a burglary alarm at all unless something beyond the alarm itself confirms it: a witness, a guard, audio or video. In those places an unverified system gets no police response, which is a fact the customer must hear at the sale, not after the first break-in.
Industry practice has also moved toward scoring alarms by how strongly they are verified. ANSI/TMA-AVS-01, published by The Monitoring Association, defines a scale the station assigns to each alarm based on the information it has, from an unverified signal to a confirmed threat to life, so the agency receives a score with the dispatch request. Whether an agency uses the score is the agency's choice.
Worked example: the same back-door alarm on three accounts
Three houses on one street, same make of panel, same back-door burglary signal at 01:30, nobody home at any of them. The times are illustrative for this example; real times depend on the station and the call list. Assume each operator picks up the signal at 01:30:20, twenty seconds after it arrives.
House 1: ECV only.
| Step | Time spent | Clock |
|---|---|---|
| Operator reads screen, calls premise, rings out | 1 min 10 s | 01:31:30 |
| Calls homeowner's cell, voicemail | 1 min 00 s | 01:32:30 |
| Dispatch request: "burglary alarm, rear door, no contact" | 01:32:30 |
Verification cost 2 min 10 s, and what the agency gets is the least it can be told. In this jurisdiction that is a low-priority call.
House 2: video verification. A camera covers the back door and its clip arrives with the alarm.
| Step | Time spent | Clock |
|---|---|---|
| Operator opens the clip: person in dark clothing forcing the door | 20 s | 01:30:40 |
| Dispatch request: "video-verified intrusion in progress, one subject" | 01:30:40 | |
| Calls premise and call list to notify | after dispatch |
Verification cost 20 seconds, the dispatch went out 1 min 50 s sooner than at house 1 (01:32:30 minus 01:30:40), and the agency in this example treats it as a crime in progress.
House 3: video verification, wrong camera. The account has cameras, but none covers the back door; the nearest one shows the front porch.
| Step | Time spent | Clock |
|---|---|---|
| Operator opens the clip: empty porch | 20 s | 01:30:40 |
| Falls back to ECV: premise, then cell, both ring out | 2 min 10 s | 01:32:50 |
| Dispatch request: "burglary alarm, rear door, no contact" | 01:32:50 |
This account paid for video and got a dispatch 20 seconds later than house 1, with the same unverified description. The cameras were placed for the customer's curiosity, not for verification. Planning camera coverage against the alarm zones is a design step, covered in How to Plan Camera Locations on a House.
The false alarm side of the same choice
Change one input: at all three houses the alarm is a teenager coming home late who does not know the new code, and the teenager does not answer the house phone.
- House 1: the premise call rings out, the second call wakes a parent who gives the passcode and cancels. No dispatch, but only because the second call was answered.
- House 2: the operator sees a teenager with a backpack letting themselves in with a key and calls the parent before deciding. No dispatch, and the operator knew why.
- House 3: same as house 1.
ECV and video both stop this false dispatch. Video stops it with information; ECV stops it with luck about who answers.
Choosing for an account
- Match the method to the agency. Where verified alarms get priority, video or audio is worth the equipment. Where the agency requires ECV, it happens anyway and the question is whether to add more.
- Video verification needs the right camera on the right zone, a clip that arrives with the alarm, and the customer's consent to the station viewing it. What the customer is told about who sees their video is part of the handover; see related: Privacy of Cameras and Sensors You Install.
- Two-way audio needs a microphone where the sound is. A panel in a basement closet hears the furnace, not the kitchen window breaking. Where the panel supports remote audio stations, place them in the main living area, and test from the station end that the operator can actually hear a normal voice from the likely entry rooms.
- Confirmation needs a floor plan that guarantees two zones. In a small home an intruder may cross only one detector; a confirmation rule there turns a real burglary into a single unconfirmed trip, or into no report at all when the rule is at the panel.
- The call list is part of every method. Even with video, the operator calls someone. A list with old numbers wastes the time video saved.
References
- ANSI/TMA-AVS-01, Alarm Validation Scoring standard, The Monitoring Association
- Local alarm ordinance and the responding agency's alarm response policy
- See related: How a Central Station Handles a Signal, from Panel to Dispatch
- See related: How to Plan Camera Locations on a House
- See related: Privacy of Cameras and Sensors You Install