Concrete ??

How much information is in poured concrete after cure ?
Class toured both a batch plant and then a testing lab for concrete . 
At test lab there was a concrete block about 1 ft in length and 2 ft wide and 2 ft depth 
Rough surface outside - 2 holes in block (kind or round shape)
 Lag tech gave info on it - was from Las Vegas area desert , holes were where legs of individual were encased after burial in desert , concrete block was cutoff of full grave site slab . 
  Lab work determined the brand of cement mix , batch date , wholesale supplier , then checking for supplier records of large sale of bagged mixes during certain dates , traced to purchaser . Murder Solved - person arrested , convicted , and lab kept a sample of the evidence .
  Seems someone killed someone , then buried them in desert but encased in concrete so as to not be dug up by some animals . Forensic information of cured concrete let to the purchaser and the date of sale from local hardware store based on volume and material content of components ...
  That concrete trophy setting in that lab, where the holes use to hold a set of legs --creepy at least .