Guidelines for the use and statistical analysis of the Home Office fingermark grading scheme for comparing fingermark development techniques.

This paper provides guidance on how to properly analyse data generated from the Home Office fingermark grading scheme. The core of the issue is that it creates ordinal data and should therefore not be analysed using averages. To reduce confusion, it is recommended to label the different degrees of fingermark development as classes rather than numerical scores.

Water content of latent fingerprints - Dispelling the myth.

Changing procedures in the handling of rare and precious documents in museums and elsewhere, based on assumptions about constituents of latent fingerprints, have led the author to an examination of available data. These changes appear to have been triggered by one paper using general biological data regarding eccrine sweat production to infer that deposited fingerprints are mostly water. Searching the fingerprint literature has revealed a number of reference works similarly quoting figures for average water content of deposited fingerprints of 98% or more.

Variation in amino acid and lipid composition of latent fingerprints.

The enhancement of latent fingerprints, both at the crime scene and in the laboratory using an array of chemical, physical and optical techniques, permits their use for identification. Despite the plethora of techniques available, there are occasions when latent fingerprints are not successfully enhanced. An understanding of latent fingerprint chemistry and behaviour will aid the improvement of current techniques and the development of novel ones.

Development of a GC-MS method for the simultaneous analysis of latent fingerprint components.

Latent fingerprint residue is a complex mixture of organic and inorganic compounds. A full understanding of the composition of this mixture and how it changes after deposition is lacking. Three solvent systems were compared for the simultaneous extraction and derivatization with ethyl chloroformate of selected amino and fatty acids from a nonporous substrate (Mylar for subsequent analysis by gas chromatography-mass spectrometry.