Search Techniques and Theory

Search Techniques

Type 1 - Hasty Search

This is a quick and efficient search by small teams that travel quickly to the likely spots and by the route of least resistance. A hasty search is generally the first tactic used in the early hours and days of a search. The hope is the subject is still alive and responsive. Most search missions end within the first day or two and never get past the hasty search mode. Resources commonly used for hasty search include ESAR, Search Dogs, 4x4 units and Helicopters.

Type 2

This is a more organized yet rapid search of a large area. Small teams of three persons are assigned an area. One-person guides on a physical feature such as a trail, creek, road or ridge top or are assigned a compass bearing to follow. The other two-team members guide off that person and search an area to either side, roaming through the brush following the path of least resistance, checking likely spots. Spacing may be as much as 100 feet between searchers. Density of the brush dictates how far apart searchers may be and the distance will fluctuate depending on the visibility. This is a very efficient search tactic, used while the subject is still believed to be responsive and will answer to voice checks. Common resources used for Type II search is ESAR.

Type 3

This is a thorough search method but not very efficient. It requires a large number of people to cover a relatively small area with a high probability of detection. It is used in the later stages of a search when the chance the subject is down and not responsive has increased. Common resources used for Type III search is ESAR.

Type 4

This is used only on evidence searches. This is a very thorough search, with team members shoulder to shoulder on hands and knees, clearing brush down to bare earth and looking for small evidence items such as weapons, bullet casings, bone fragments, etc.


This is a type 1 or type 2 search in an urban setting rather than a wilderness setting. Searchers are asked to look for hiding spots and be more alert to the possibility of criminal acts associated with the missing person. They must also be more aware of hazards associated with urban settings to include traffic, animals, private property, industrial sites, chemicals and confined spaces.

Search Theory

Search is an Emergency

A SAR response must be rapid and effective. The subject may need emergency care, may not be able to protect himself or herself from the environment. Time and weather destroy clues and an urgent response and deployment of resources may reduce the size of the area that must be searched, making the area easier to search. The chance of success is directly related to the size of the search area. 

To respect the subject's emergency, modern search theory dictates that:

  1. Respond urgently
  2. Search at night
  3. Mobilize quickly and keep searchers in the field
  4. Create an atmosphere of positive urgency

Search is a Classic Mystery

Trying to determine what happened will often lead searchers to the subject. All of the clues are usually there if the search manager properly investigates interviews and interprets information from the field.

  • You must know what clues to look for
  • Determine possible destinations
  • PLS must be identified
  • Must recreate the circumstances behind the disappearance
  • Subject might be somewhere else

Search for Clues

There are more clues than subjects. Every subject on land leaves clues such as scent, tracks and other disturbances. Clue detection will substantially reduce search difficulty.

Concentrate on issues that are important to the search success and under the control of the manager. It is a waste of time, energy, effort and money to do otherwise. Weather, terrain, subjects actions are all beyond the control of the manager or the search teams.

  • Know if the subject leaves the search area
  • A search without a subject is nonsense
  • Search difficulty increases rapidly unless you confine the subject to a small area
  • Check all possibilities including home, hospitals, friend's etc.
  • Grid search as a last resort. It is not an efficient use of resources.

Planning Data

Information required for adequate search planning:

  • Category of the subject, hiker, hunter, child, elderly etc.
  • Point Last Seen PLS or Last known Point LKP
  • Circumstances of loss
  • Length of time since last seen or overdue
  • Subjects trip preparations
  • Experience
  • Physical condition of subject
  • Medical condition of subject
  • Personality traits
  • Weather then, now, future
  • Terrain analysis

Searching Data

The information that each searcher needs to know. Without this information, it is senseless to commit teams to the field.

  • Name to call
  • Clue information, (Clothing, equipment etc.)
  • PLS or LKP
  • Search area assignment
  • Command structure

Point Last Seen (PLS)

This is determined by someone who actually saw the person and can pinpoint where they were on a map. This is useful if the point is somewhere along the intended route of travel or at location within the search area. It is useless when the PLS is the subjects home as they were leaving on the trip. Such as the wife who reports her husband overdue on a hunting trip. Last seen as he drove away and was going to hunt somewhere in western Washington.

Last Known Point (LKP)

LKP may be more useful in some cases than a PLS. It may be the subjects car parked at the trailhead, the abandoned campsite, the verified piece of equipment found abandoned in the woods, the subjects signature in a summit log book. No one actually saw the subject there but evidence and clues are just as good to place the subject at that location at some point after they left on the trip. All these items narrow the search down and refocus it. There may be only one PLS but there may be several LKP discovered as clues are found and verified.

Likely Spots

A likely spot is any place that may attract a lost person or a geographic feature that could be the cause of the subject being overdue. Examples may include water, mine shafts, caves, shelters, viewpoints. Geographic features that can cause problems include steep terrain, fast rivers, switchbacks, cliffs, drainage's and terrain that tends to direct a person's direction of travel. These are places to search first with hasty teams and things that search teams should be alert for while they search. Trying to determine what happened to the missing subject is a significant part of any successful search.


This is a tactic used to limit the area of the search. By establishing road blocks, trail blocks and putting boundaries up that the subject should not cross the area that must be searched initially is limited. It must be done early and at a distance far enough from the point last seen or the Last known point that the subject cannot have already passed by that location. This is of limited use and is not often utilized.


The use of lights, horns, voice checks, whistles, smoke or any other device for visual or audible signaling can be used to alert the missing subject to the direction they need to travel to find help. Most subjects found by hasty teams are found with voice checks long before there is a visual sighting. The concern regarding the use of attraction is the potential for drawing the subject into a hazard if they try to travel to the signal at night when visibility is poor. Trying to walk to a horn or a light the subject could walk off a cliff.


All search teams should have some tracking training. Finding tracks or other signs of a subject passing are excellent tools in reducing the size of a search area. The most significant problem with tracking is making sure the sign or track is in fact made by the subject who is missing and not by some other person or searcher.

Clue Aware

Searchers must be made clue aware so they do not overlook the potential clue left by a subject. There are far more clues in a search area than there are subjects. Clues include abandoned camps, equipment and clothing, candy wrappers, footprints and scuff marks, smoke from a fire, emergency signals, voice response to voice checks.