The forensic significance of the correlation of density and refractive index in glass evidence

Abstract

The high correlation of density and refractive index has tended to obscure certain aspects of the interpretation of glass evidence. The fundamental relationship of the two properties are examined here from the standpoint of composition and heart treatment, and considerations which may lead to conceptual errors in the interpretation of provenance are identified. An argument is presented for the necessity of an absolute determination of both refractive index and density for the proper forensic interpretation of glass evidence data. By doing so, the analysis may be extended to the constrained limits set by within-item variation.