I am sitting on a jury trial in which a detective for one of the local police departments described their procedure for locating items of evidence at a crime scene so that the crime scene can be later reconstructed. Their procedure, which he refered to as triangulation (more on this later) is:
[ol]
[li]Locate two fixed points and call them X and Y.[/li][li]Using a tape, measure the distance from X to the item to be located.[/li][li]Using a tape, measure the distance from Y to the item to be located.[/li][li]If the item to be located is on the straight line between X and Y then find an alternate fixed point Z and measure from it and either X or Y.[/li][/ol]
Perhaps I am totally out-of-it, but given this last criteria, this procedure will not fix the location as the procedure identifies two intersections both having the same distances to X and Y. To fix the location, they would have to use triangulation and pick a third reference point and include its distance to the item to be located. I might also add that their field drawings are no where near accurate enough to clearly indicate which intersection point that they might be describing relative to points X and Y.
If you locate something by reference its distance from two points yes, you are identifying two possible locations. To narrow it down further you also need at least a relative indication - e.g. the thing is equidistant from points A and B and north of the straight line between them or to the left of point C or on the tennis court (assuming only one of the two possible locations is on the tennis court).
The sketch maps don’t have to be very accurate to provide the necessary relative indication; they certainly don’t have to be to scale, or anything like that. Even a crude sketch map could satisfactorily show, e.g. that the item concerned was located this side of the line between points A and B rather than that side. (The other possible location will always be on the other side of that line.)
Yes, your statements would resolve the problem but the sketches and notes provided by the detective were not accurate enough to make those distinctions (e.g., north of the line between X and Y). What really got my attention was they specifically called out what they were doing as being “triangulation” yet they failed to make the connection that a triangle has three sides!
I think the trick is to choose X and Y such that all potential points of interest are on the same side of the line that connects X and Y. If you do that, the distance from X and Y defines a single point in space.
There are three sides. If the object to be located is O and the reference points are X and Y, then the three sides are OX, OY and XY.
Given the fixed points X and Y and the lengths OX and OY there are two possible locations for O, one to the right of the line through XY and one to the left of that line. (I omit the case in which O is on that line, in which case there is only one possible location for O.) Even a crude sketch should be capable of showing whether O is to the left or right of that line although, of course, you have seen the sketches and I haven’t. If the sketches are so poor that you literally cannot tell whether O lies to the left or right of a line drawn through points X and Y then, yes, on the information supplied you cannot locate O. You can narrow down its location to two possiblities; that’s all.
And since we live on a planet with gravity, following the curve down to the point where the object is sufficiently supported, such as on the floor or a table, should work in 99% of real world situations.
Fundamentally, I’m failing to see how the technique would produce results innaccurate enough to raise the possibility of reasonable doubt in and of itself- it isn’t going to put an object in the wrong room.
To be honest, it surprises me the the state is producing sketch maps so badly drawn that they do not clarify which of only two possible points an object can be located at. But I haven’t seen the sketch maps and Waterman has and he says yes, they, are that bad.
Waterman hasn’t said whether uncertainty over which of two points any of the relevant objects might be at is going to be fatal to the state’s case. It could be, but it won’t necessarily be.
Waterman what are you doing? If you are really sitting on the jury you have to go tell the judge that you violated his instructions so you will be removed from that jury.
I am not a lawyer, but when I served on a jury we were given instructions not to discuss evidence outside of the jury room. I am therefore going to have to close this.
If anyone has better legal knowledge than I have and can cite why this discussion is legally permissible, send me a pm with an explanation of the legal issues and I will re-open this.