•It is difficult to predict future events. It is even more difficult to predict future predictions of future events.

As you know, I have a particular axe to grind. I am interested in the dynamics of proof in litigation.

I am also troubled by what I think is the lack of understanding in the legal profession of the workings of proof in litigation -- or, more accurately speaking, I am troubled by my own lack of understanding of the workings of the process of proof in litigation.

In trying to figure out how the process of proof works I have often -- see, e.g., http://tillers.net/decision.html, -- I have often asked myself the following question:

Please consider the following story:

I live in a small house in the country. A long winding driveway, covered with loose gravel, leads from the county road to my house.

One day as I leave my house for a walk I see what appears to be a green spot on the driveway that leads from my house to the county road.

I walk on.

Alt. 1: I stop and approach the spot.

Alt. 2: I put on my glasses.

Alt. 3: I walk back into my house.

Alt. 4: I walk over the spot and scuff it away with the heel of my shoe.

I see what appears to be another green spot.

I think, "That looks like moss."

Alt. 1: I think, "That looks like tar pitch."

Alt. 2: I think, "That looks like cow dung."

Alt. 3: I think, "That looks like the remains of an alien being."

I walk over to the spot and sniff it.

Alt. 1: I walk on.

Alt. 1A: I see another green spot.

Alt. 1B: I see no more green spots.

Alt. 1C: I keep my eyes to the heavens, looking for peregrine falcons.

Alt. 2: I turn and walk back into my house.

Alt. 3: I walk back to the first spot and I put on my glasses.

I think, "Funny. I don't smell a thing."

I think, "That smells like $%^&#."

I think, "That smells like a dead rat."

I think, "That smells like moss."

I turn and walk back into my house.

Alt. 1: I scratch the spot with my thumb.

Alt. 2: I cover the spot with gravel.

That night there is a drenching rain. I go out the next morning and see that the spots are still there.

Alt. 1: I see that the spots are no longer there.

Alt. 2: I see that the spots are now blue.

Alt. 3: I do not go out the next morning.

I approach the second spot. I see three more spots further down the driveway, several yards past the second spot.

...

I think to myself, "Where did those ^%$@*& spots come from? They're ugly."

Alt. 1: I think to myself, "Another day, another spot."

Alt. 2: I think to myself, "I'd better stop wasting my time and I'd better get back to work."

Alt. 3: I think to myself, "When I was a kid I would have spent hours examining something like this. Now it's just a green spot. Have I lost my sense of wonder? Sad. Well, there's no going back."

I walk over to the last spot. I stick my finger in it. It feels like soft plastic. I smell my finger. I think, "This smells like oil."

...

I think, "My car doesn't have any oil leaks. This is the doing of the fuel oil company."

Alt. 1: I think, "I don't think my car did this. This is the doing of the FedEx delivery truck."

Alt. 2: I think, "My car must have an oil leak. But I just took it in for servicing. Those %$#@* fools must have mucked it up."

Alt. 3: I think, "It's the neighbors' kids. They've been playing over here with their dirt bikes again."

Alt. 4: I think, "I wonder if those jet airplanes have been flushing their fuel tanks again?"

Alt. 5: I think, "Is that really oil?"

This little episode (above), the upshot of which is yet unclear, involves a considerable amount of serendipity. But the episode that I have described also involves some directed activity, activity that seems to have an epistemic focus or purpose. So I would not say that the events that I have described illustrate the hypothesis that all aspects of forensic investigation and proof are serendipitous. But they may illustrate the hypothesis that both serendipity and luck play a large part in investigation and proof and that it is very hard to predict the upshot of any investigative act. (Consider the decision by the actor in the story to stick his finger in the green spot and the discovery he makes when he does so.) The world is full of surprises that can be uncovered only by actually looking (or poking with a finger, or smelling, as the case may be).

Consider the following diagrams:

 

Now I have not demonstrated, nor have I tried to demonstrate, that the course of investigation and proof is unfathomable. It is mainly my intention to pose a question, to frame a problem. Moreover, I have exaggerated the problem: by emphasizing the front end rather than the back end of the process of proof, I have accentuated the unpredictability of the process. (The course of proof is generally less stable and less predictable during pretrial investigation than at trial; generally, matters such as legal issues, and the identity of sources of evidence such as witnesses have settled down, have become more stable, by the time of trial.) Nonetheless, I believe I have deposited a serious problem in your laps. I have done so if it is true that the quality of the concluding chapter of the process of proof depends on the quality of the chapters that came before. If there is anything at all to what I have said or suggested, a great mystery of legal scholarship in Evidence is how the front end of the process of proof should be regulated. For if something like serendipity, luck, or surprise plays a large role in investigation, it may be very hard to describe the patterns or channels that law should force investigation to take.

•My tentative solution to the problem -- the problem of enhancing the accuracy of a process whose optimal course is hard to discern -- is to focus on the preservation of the integrity of sources of evidence. Cf. my essay, "The Fabrication of Facts in Investigation and Adjudication."

• For a more extended but differently-articulated discussion of the themes discussed above, please see my comments on the "explosive dynamic complexity" of evidentiary processes.