Spherical coordinates for plotting the positions of powder residues.

The idea of the “Reconstruction of the Crime” as an aid to its solution was first succintly expressed and practiced by Alphonse Bertillon [1] toward the latter part of the nineteenth century. Since that time investigators have aimed at ever more detailed descriptions and reconstructions. The phases of description and reconstruction employ procedures very similar to those employed in the compilation of maps. The mapping quality is the basis for the experiments to be described in this paper.