Brookings County K9 Search and Rescue
Brookings County K9
Search and Rescue
Brookings, South Dakota
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).
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.
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 Search
Depending 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.
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
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.
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
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
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".
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
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
5. Be properly clothed and
6. When talking to another searcher
at night, be careful not to shine your
headlamp into his dark-adapted
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
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
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
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
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
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."
Great books to have in your SAR
library. "Lost Person Behavior"
by Robert Koester. "Urban
Search" by Young and Wehbring.