Searching for Lost Persons

Finding Lost Persons is both simpler and more difficult than most people realise. This is sounds crazy but I hope to be able to explain this in the fullness of time.

To find a missing person, you need to look where they are, and eliminate areas where they aren't. It's that simple. But how the hell do you do that? If you knew where they were, they wouldn't be lost! ... well, yes... and no.

Have you ever lost your keys? How did you search for them? Did you start at the north-west corner of your yard and systematically grid search every square metre of the yard, then proceed to search inside the house and garage in the same manner? I bet you didn't. I bet you started looking where you thought you left them last, and moved on to other places you were likely to leave them, such as where you've been, other places you often put them, etc. In this way you naturally searched the high probability places first - the places where the keys were most likely to have been. This gives you the best chance of finding the keys quickly and with minimum effort.

So, did you know where the keys were? No. Did you know where they were likely to be? Yes. Was there a system to your search method? Absolutely! From highest to lowest probability of where the keys were likely to be. In Search and Rescue (SAR) parlance, this probability is Probability of Area (POA), or the probability that what you are looking for is in that particular search area,

So why do so many SAR authorities and agencies insist on teaching people to "line search"? i.e. form up in a straight line and search an area methodically. The answer lies in the history of line searching. It was first used by ancient hunters to flush game out of undergrowth so they could capture or spear it, and was later used by armies of all denominations to systematically clear areas of hiding enemy soldiers. In these situations, the line search is entirely appropriate. In searching for a lost person, it is rarely appropriate.

A lost person, it can be assumed in most cases, wants to be found. Wild game, an enemy soldier, or an escaped criminal, for example, do not want to be found. They are not "lost" - they are evaders. People who want to be found and people who do not want to be found fundamentally need to be searched for in different ways.

So why isn't line searching appropriate for finding missing persons? Time. A lost person has an expected Time Frame for Survival (TFFS). The TFFS depends on the person, the weather, the climate, supplies the person has, etc. Generally, when a person is reported missing, there has been a certain time elapse since they were last seen, then there is the time taken to respond search teams, and organise the search. Usually by the time the search has started, the possible search area is so large that it is not possible to search that entire area by line searching in less than the subject's TFFS. So there is a real risk that by line searching, the missing person will be found, but too late.

The other aspect of time in the search situation, is that unless the initial search area is effectively confined or contained, it will continue to grow. It grows in radius by the maximum speed that the subject can be expected to travel at. For example, assuming moderate bushland, a walker can travel at about 3 kilometres per hour. If it takes an hour for the subject to be missed, another hour of searching and travelling to raise the alarm, and an hour for searchers to respond, the search area is already 254 square kilometres in theory! If it takes another hour to get organised to confine the search area, the search area has now expanded to 452 square kilometres! Time is of the essence! This is why searching is an emergency!

So what do we need to find lost persons?

1. Urgency. Respond NOW! ...or have a very good reason not to. You may cop some criticism for over-reacting - big deal! On the occasion when the rapid response saves a life, you will appreciate not having to explain to the coroner why you delayed. The response must be proportionate to the worst case scenario that is possible for the missing person(s). Until located, you do not know what fate has befallen them.
2. Confinement. The first practical thing to do in the field is to confine the search area - stop it growing. Confinement of the Point Last Seen (PLS) or Last Known Point (LKP) is important until trackers can extract as much information from the area as possible.
3. Intelligence. You need to know the search subject as well as you can: capabilities, interests, limitations, phobias, skills, appearance, etc. Lost Person Behaviour Characteristics are a great tool. You need to know the search area: attractions, barriers, passes through barriers, hazards, places that facilitate common navigational mistakes, shelters, water sources, campsites, etc. This is typically in the form of local knowledge. It is vital.
4. Skilled searchers. They must be skilled to handle all the conditions they may be expected to find in the particular search. A skilled searcher from one area of the country is not necessarily a skilled searcher in another. An alien environment can quickly bring an ill prepared or skilled searcher undone. They must be skilled in survival; navigation; local knowledge; clue detection, documentation and preservation; communications and team work and leadership to name just a few areas. Training does not mean a person is skilled! Searchers must be fit enough for the operational demands of the search and the terrain.
5. Attraction. Use light (at night) and especially sound to attract the attention of the subject. Some lost persons, such as little children, will have characteristics of evaders and not respond to attraction methods for fear of getting into trouble, so this must be taken into consideration.
6. Skilled Search Planning. A disciplined probabilitistic approach where clues and the absence of clues steer the searchers to the subject. Search planning should not be done by a single person. Two to four people work best to try to avoid tunnel vision and missing possibilities. A single dominant personality in the search planning team can result in "Group Think" and subsequent errors in judgment, so should be discouraged.
7. Aggressive Searching Techniques. Use of small hasty teams of skilled searchers, to travel quickly to search and penetrate the search area while applying intelligence, tracking and clue detection skills.

Back to Al's Search and Rescue Notes

Back to Al's World