Silver Alert Concept

Most of us are familiar with an Amber Alert. You’re driving and you hear this sound on the radio, followed by a description of the child who is missing, the person suspected to have taken them, and usually a licence plate.

You didn’t know about the licence plate? Take a look at the Amber Alert criteria, it’s very specific to child abduction. The original idea behind the Amber Alert includes the concept that the alert had to have a fairly large geographic region because the abductor was fleeing with the abductee, usually in a car. This is why Amber Alerts are displayed on road signs, and are on the radio – because the target audience is a driver who might see the car.

Now let’s consider a Silver Alert.

We have many examples of the Silver Alert throughout the United States, and the people behind the BC Silver Alert have developed our own activation criteria based on the work of many of these programs. Like the Amber Alert, they are very specific. However, what we have not published is guidance on how we conceive the Silver Alert to be implemented.

Range and Audience

The target audience and geographic area of the Silver Alert is not the same as that for an Amber Alert.

Missing people with dementia, autism or other cognitive deficits are not usually driving. They are on foot. Based on the experience of local Search and Rescue teams and on specific reasearch into the topic[Koester2008], such a person may be found in any of the following situations

  • riding transit
  • walking along a street
  • in a public area like a park or mall
  • in an urban back yard
  • in a green space, often in the bush
  • in a building

Additionally, research suggests that 95% of subjects meeting the criteria for dementia are found within 12.5 km of their point last seen, and 75% are found within 3.2 km[1]. Further analysis of data consisting of searches for people with dementia just in British Columbia by Ridge Meadows SAR Manager Richard Laing[2] concludes with slightly different numbers, but within the same range. The following table summarizes the findings

Category 75% 95%
Dementia [Koester2008] 3.2 12.5
Dementia [Laing2013][2] 4.1 6.61
Autism[3] 3.8 8.0
Mental Retardation[4] 3.7 9.9
Maximum 3.9 12.5

Based on the research above, we can make some very intelligent guesses as how large an area, and how many people need to be alerted for a Silver Alert. A 12km radius would be likely, and in British Columbia this would encompass just one or two municipalities.

Additionally, our guidance to the public is that there is little need to share or respond if you are outside the target area; spreading a Silver Alert to other cities and regions serves little purpose.


We envision the following for the silver alert, presented as a scenario based on first hand experience with a missing person with Dementia.

Alert sent to:

  • People within 4-12 km of point last seen.
  • select people
    • by home address,
    • current location (geographic)
    • municipality
    • sub regions within the circular radius.

The alert text will contain:

  • the official agency requesting assistance
    The agency should be the local authority, usually the police of jurisdiction
  • missing person’s name (first and last) and nick name or “known as”
    People sometimes respond to a name different to their official name
  • missing person’s age
  • missing person’s silver alert criteria
    This can help people understand the urgency
  • last known location and time
    Public can judge how close they are to this location
  • link to detailed information with picture and description
    Alert can be short, but additional information can be contained in a link to the agency’s web site
  • instructions on likely areas to search
    Most of the time these will be the same, sometimes missing people will have particular habits and this can give guidance
  • contact number for reporting information
    This is essential: sometimes this information is missing

Example 1

A member of the public at home hears a distinctive alert from their mobile device. He reads the alert which states the following:

<agency> requests assistance locating missing <Firstname> <LASTNAME> <age> years old with dementia last seen at <location> at <time>. Description / photo at the following link: <link>. Please be on alert for this person, check back yards and out buildings, green spaces and public areas near where you live. Call <number> if located.

The person realizes that the missing person is just 2 km from where they live. Later in the day they look into their back yard, and over the fence into the neighbour’s yard where they see someone lying under a bush. They offer first aid, and call the number in the alert.

Example 2

A member of the public hears a public announcement on transit, and sees the following text on the public display system

<agency> requests assistance locating missing <Firstname> <LASTNAME> <age> years old with dementia last seen at <location> at <time>. Description / photo at the following link: <link>. Missing is known to take transit. Call <number> if located.

She realizes she is very close to that location and a few minutes later notices the missing person on the bus with her. She calls the authorities and the person is returned to their family.


The concept of the Silver Alert that we propose is not the same as an Amber Alert. It targets a different audience, and a different geographical area. It also asks for a different kind of response from the public.

Research and experience tells us that subjects of a Silver Alert may be in plain sight in public, in back yards, on transit or on the street. The public will be given specific directions on where to look, and what to do if the person is found.

We believe that a properly crafted Silver Alert can be targeted to a specific geographic region, and alert the right people to initiate a response. We believe that this could serve to save lives for the most vulnerable missing people.

[1] Lost Person Behaviour – Dementia, Robert Koester, 2008 p 164

[2] Analysis of Missing Dementia, Richard Laing, 2013

[3] Lost Person Behaviour – Autism, Robert Koester, 2008 p117

[4] Lost Person Behaviour – Autism, Robert Koester, 2008 p208