Rules for Investigation

Searching for boundary evidence is an investigation. It is an investigation into a scene, not a crime scene, but a scene nonetheless where the investigator is searching for evidence, and for clues when evidence is absent, or not readily visible. Crime scene investigators are highly trained for their tasks, and sophisticated scientific techniques are usually employed. Other investigations, if taken to the same level, and applying appropriate techniques, can also be very successful in locating valuable evidence.

Many of the same techniques can be employed to both types of investigation, even if the evidence sought and the tools employed might be quite different. One thing doesn't change—the thought process and the scientific process of reasoning. Sherlock Holmes made a habit of explaining his reasoning throughout his stories. Today's sleuths have attained higher levels, and reference materials demonstrating and analyzing methods of reasoning are readily available. Learning this part of the investigative process is like learning the multiplication tables for the first time. There did not seem to be any immediate practical value to the fact that 2 times 2 is equal to 4, but it did make sense that it might be useful at some time in the future. Such it is with the science of reasoning, especially when translated into practical rules, and more so when illustrated with examples.

Good investigators know that lists of questions from officially issued procedure manuals have limited use. Reading the signs and asking questions at a site does not involve completing a form or responding to circumstances by following pre-established rules. Each site, perfectly preserved or irrevocably compromised, has unique elements that modify the questions and define the playing rules for that particular site. Asking the right questions, of oneself or of others, depends on identifying the rules of each new challenge.

Reasoning backward analytically at a scene involves discovering the rules while playing the game. Sherlock spoke of that in A Study in Scarlet: "In solving a problem of this sort, the grand thing is to be able to reason backwards. That is a very useful accomplishment, and a very easy one, but people do not practise (sic) it much. In the everyday affairs of life it is more useful to reason forward, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically."

There is no place for guesswork in an investigation, it is much too serious for that. Thinking logically does not involve guessing. Guessing is blind and riddled with doubt. Guessing is merely desperate, and is not necessary where there are ordinary facts, as facts raise no doubts. Gil Grissom, the team leader of the popular TV show CSI, is quoted as saying, "concentrate on what doesn't lie: the evidence."

Yesterday, Sherlock Holmes, and today, scientific reasoners, employ the art of Abdictive Reasoning. Abduction is the process of finding a best explanation for a set of observations and it leads to subtle implications for evidence evaluation. It is about certainty and the logico-computational foundations of knowledge. Abduction can be described as "inference to the best explanation," which includes the generation, criticism, and possible acceptance of explanatory hypotheses. What makes one explanatory hypothesis better than another are such considerations as explanatory power, plausibility, parsimony, and internal consistency. In general a hypothesis should be accepted only if it surpasses other explanations for the same data by a distinct margin and only if a thorough search was conducted for other plausible explanations.

Ask any forensic investigator to name the biggest problem that they encounter on the job and you will consistently hear the same response—crime scene contamination by others. Surveyors encounter that on almost every scene, and the older the scene, the more likely the contamination, or compromise. Developers won't even hire a surveyor until the soil testing is completed. Backhoes have an uncanny way of seeking out the corner evidence and running over it. Rule Number 1: Protect the scene. Once evidence is lost, opportunities are lost. And the investigator may never know what was lost when a scene is not controlled. State guides for police practice on crime scenes state, "once the scene has changed, you cannot change it back."

Most investigators will not visit a scene alone. It is always a good idea to take someone on an investigation with you. Another person, or preferably more than one, will most likely see something that you may not. It is always good to have independent corroboration of a scene.

A good investigator will keep his or her perceptions clear. If on the scene for awhile, bring something to eat and drink. Avoid anything that could impair the senses like alcohol.

Most investigators will do their research first, trying to find out as much about the site as possible. Without research, you cannot know what you should be looking for, nor can you know what you have when you do find something.

Some investigators make it a practice to arrive at the scene with skepticism. While one should always maintain an open mind, remember that there just may not be anything out there. By doing the homework first, one gets an idea as to what to expect.

Beware of false readings. Measurements, mathematical closures, magnetic attraction, errors in reported information can all lead to false conclusions or provide false leads. Make sure that equipment is working properly, that the operator knows what he or she is doing, and that you are on the right parcel of land, not the neighbor's land or some place totally irrelevant.

Most investigators will take lots of photographs, digital or otherwise. Make certain you have plenty of film and you know how to take good pictures, with or without a flash. If you are not a good photographer, bring along someone who is. The next time you visit the site the conditions may have changed—dramatically, or the evidence may have been totally obliterated.

The above rules, at the very least, should be second nature to any successful investigator. Sometimes it is easy to find and locate the evidence, but explaining procedures or a lack of success to a judge or jury may be entirely another matter. People watch television, and they watch shows like CSI, and have come to expect from the practitioner what they see and hear on television. The well-advised will make certain that good and careful work, successful or otherwise, is not compromised or discounted by those who have a different expectation.

About the Author

  • Donald A. Wilson, LLS, PLS, RPF, Land Boundary Consultant
    Donald A. Wilson, LLS, PLS, RPF, Land Boundary Consultant
    Don Wilson is president of Land & Boundary Consultants, Inc.; and part owner of and the lead instructor in Surveyors Educational Seminars, a member of the Professional Surveyor/RedVector Dream Team providing online courses for continuing education; and a regular instructor in the University of New Hampshire Continuing Education System for 25 years. He is also co-author of several well known texts.

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