top of page

Search Theory


Great books to have in your SAR library. Lost Person Behavior by Robert Koester. Urban Search by Young and Wehbring.

When Searching

1. Sign in when arriving at the search and sign out when leaving. This is done to account for all searchers, to make sure they all made it out of search areas OK.

2. Keep alert. Use your eyes, sometimes your nose, and always your head. Take your time and don't miss anything. You may not get another chance.

3. Make some noise, but also be quiet at times to listen for the subject. This is a good technique at night when the subject is thought to be uninjured or at least conscious.

4. Call out the name of the lost person. You should have learned the name and description of the missing person including type and color of clothing, prior to leaving base camp.

5. Be properly clothed and equipped.

6. When talking to another searcher at night, be careful not to shine your headlamp into his dark-adapted eyes.

7. On a line search [grid search] learn the names of the searchers to each side and don't change your outer layer of clothing without their noticing.

8. Bright colored, highly visible clothing is always appropriate in the mountains and is particularly important in line searches.

9. Searchers should always use common sense, checking the obvious. For example, looking in buildings which would make good shelter, inquiring of hikers encountered along the way, or even checking with anyone seen walking along a road near the search area, since such a person may be the missing one.

10.The safety of the searchers is more important than the search itself. If the individuals or teams are put in danger because of lack of personal skills for the terrain or due to hazards or weather, that part of the search must be temporarily abandoned.

11. Care must be used in the choice of words spoken over the radio, because press and relatives may be listening to every word, and prearranged code words may be required. All messages should sound routine.

12. It is very important for individual searchers to maintain a proper attitude towards the search. Searching is hard work, rather boring and tedious, and usually does not turn up anything. If an individual cannot discipline them selves to be an effective searcher in spite of bad weather, fatigue, and discouragement, they should sign out of the search area and not discourage those who can.

13. When in the base camp area, individuals should stay out of the mission headquarters. Loose talk about the mission must be avoided in base camp, since a casual remark may be overheard by the press or may be the origin of a distracting rumor.

14. Only the incident commander or search manager may give information to the press. The best response to a question about the mission from any stranger is, "I don't know. Ask the search manager over there."

POS - Probability of Success

By the time Search Dogs are called to a search, Law Enforcement or initial responders will have established the place the subject was last seen (Point Last Seen / PLS by witnesses) or the place the subject was last known to be (Last Known Point / LKP such as an abandoned vehicle, subject's clothing on trail, etc.) Normally dogs are started at the PLS or LKP so they can determine the direction traveled by the subject so that resources can be concentrated in the correct direction or search area. LE should keep these areas as free of contamination from other people as much as possible. With the point the subject was last seen as the center, Search Managers draw a 360 degree circle around it. This is called the search perimeter. Depending on the length of time in which the person was last seen and the time searchers show up, will determine how big the circle will be.


Studies have been conducted that help Search Managers determine how far a person can travel in a certain amount of time. The chance of success is directly related to the size of the search area. Refer to Lost Person Behavior book by Robert Koester. Search Managers determine how to deploy resources to areas that will increase the Probability of Detection (POD). The goal of search planning is to increase the Probability of Success (POS) as quickly as possible with available resources.


LE will provide a description of the lost subject (if known). That description may include the subject's sex, age, size, weight, hair color and clothing worn. Searchers will be briefed on the situation status, subject information, terrain in the search area, hazards to expect, weather information and much more. As Search and Rescue volunteers, our goal is to recover a lost individual but it is important to understand that we are not just looking for a person, we should also be looking for any clues (or sign) that the lost subject may have left behind. There are ultimately more clues than there are lost individuals. Clues or sign gives us a direction of travel, thereby reducing the search area and increasing the POS (Probability of Success).


Search Techniques

Initial Search

Quickly searching the likely places the person would go, can often eliminate a search before it really begins. LE will gather the latest information about what the person's plans were, what they planned to do later in the day, where they are staying, who their friends are in the local area, who they might have met recently, etc. Communicate quickly with command because it allows search planners to quickly rule out obvious areas. As always, be alert for clues, both discovered clues and comments from people who know the person.



LE may assign squad cars to patrol the outside perimeter of the search area. Volunteers may also be assigned to watch long stretches of road or open fields. They are basically waiting for the search subject appear. While this may be a boring job, they need to stay focused. They need to be 100% certain that the lost person does not get past them without being spotted.


Hasty Search
A Hasty Team search will usually consist of ten to twelve highly trained searchers. This team should include Search and Rescue canines and possibly mounted teams. They will quickly spread out in pairs looking for clues or the lost person in obvious places. The goal of a hasty team is to move quickly through the search area checking places where a person might be injured or might have stopped to rest. By putting a well trained team into a high probability area, the search leaders are hoping to find the subject with a quick pass. If the person is truly just wandering around in the woods, then the hasty team will find them and bring the search to an end.


Choke Point

SearchDepending upon the lost person's skills and the terrain, some searches lend themselves to choke point searches. If your search area includes a large river with only a few bridges, then you have an excellent opportunity for a choke point search. Think of this as a roadblock rather than a search. A small team is assigned to cover the choke point, to ensure that if the lost person attempts to pass through that point, you can identify him.



Calling the subject's name, blowing whistles, using sirens, lights, etc. are forms of attracting the subject to move towards them or respond in some way.


Track Trap

A track trap is a spot which will capture a person's footprints. Even if you cover your tracks; there is still evidence that someone has passed through the area. There are many natural track traps, which include river and stream banks, trails with excessive mud or dust, thorn bush thickets and even sand pits.


Other - There are other features that might also affect a person's choice of route. For instance a person may follow a fence line, pipeline or utility line in order to reach civilization. Items such as towers, lights, and beacons can attract a lost person and affect their direction of travel. Mountain peaks or terrain features that are visible from far away might cause a person to follow a certain path. Any one of these "Route Modifiers" could be used very effectively to determine a direction of travel.


Grid Search

A Grid search is what the public usually thinks of when they think of a lost person search. They picture a straight line of people walking across an open field. Because of the number of people and time needed, this type of search should always be done as a last resort. Grid searchers rarely find the subject; however, they almost always find any and all clues which might be in the area, assuming the searchers are reminded to be clue conscious.


Clue Awareness

Looking for clues begins the moment a person is determined missing and ends with the final search debriefing. Look for all clues. Do not only look for clues that you think should be out there based on any prior information. Here are a few examples of clues you may find:

Physical: Footprints, candy wrappers, cigarette butts

Recorded: Trail logs, notes, telephone messages.

People: Reporting party, friends, eyewitnesses.

Event: Smoke, lights, sound


Looking Guidelines

Change views from the big picture to small objects regularly. Your eyes can tire quickly. Look behind you on a regular basis. This will give you a different angle of view. Look for visual cues, not for preconceived shapes or objects. Move in and inspect more closely anything that seems out of the ordinary. Avoid any preconceptions and look at everything. Take your time. There will usually be a lot to see and this may be your only chance to find an important clue. Do not walk or ride (vehicle or horse) down the middle of a dirt trail. If your search subject is on foot he is also likely to walk in the middle, and you will destroy tracks. Travel on the sides of trails and roads. Before you drive/ride on dirt roads, get out and cut for sign.

bottom of page