What material most closely resembles/emulates dog's excrements? Please get me right - this is no joke!

Our engineering team has a terrible contract - we need to find a way to get height from which some dog excrements were dropped judging by what was found on earth when it hit the ground. We need to find some invariant in excrements form, scattering of droplets/material, I don't know whatever else...

We did not start math modelling yet, because it makes no sence - we need to get somewhere physical propeties of "material", besides it is clear that the best way to start with is real-life experiments - but throwing such stuff from different heights over and over again is definitely a bad idea.

The best solution would be to find some material which is maximally close to what our target is - like ballistic gel instead of a human body.

Sorry to ask, but what material most closely resembles/emulates dog's excrements?

So far we found nothing in literature, maybe at list please a hint where to look for...

Sorry once again - this is absolutely no joke, this is for real. The height is within 70 meters limit (this is the max height), the surface is hard - it is pavement (just where people walk). Actually we need to create methodology allowing to calculate from what floor of a building it was dropped (or proove that required resolution of 2-3 meters cannot be reached) by teenage pranksters who do it regularly in different locations (they play it from their rooms and they are networked through some kind of viral social network). This is a real-life problem and we understand why it arose, but it is terrible from the technical point of view.
You'll never be able to get to 2-3m accuracy with this. With a reproducible sample, you could make a few dozen tests and create a convincing statistics.

But dog excrements? Even if they always used the same dog, which they kept on a constant diet, and which you had impounded, it'd be impossible. The sample is much, much too complex, and, unfortunately, very much alive. (I don't mean the dog.)

I say stick to old-school policework: Keep interrogating your pranksters until one of them sings. ;-)