S.S. Kind

The Use of Ammoniacal Bloodstain Extracts in ABO Groupings

Extractive versions of the Absorption Elution Test for bloodstain grouping have the advantages of suitability for batch working and the ease of reading the results. The unpopularity of extractive methods, however, can be traced to the difficulty of bloodstain extraction in all but the freshest of stains. It has been shown that dilute ammonia solutions are excellent extractants of denatured bloodstains for ABO grouping. The method should find particular application in warm climates where the heat denaturation of bloodstains is a daily problem for forensic science laboratories.

The assessment of information content gained from the microscopical comparison of hair samples.

The term “objective” is usually applied to methods where clearly defined logical steps are taken in an analysis and where the results can often be defined on a numerical basis. Subjective comparisons are, by contrast, those where discrimination is based on the intuitive (non-numerical) perception of the observer and where the ei idential value of the discrimination is doubtful. In the present study a short series of “unknown” sample pairs of human head hair have been microscopically compared by an observer trained in microscopy but not in hair comparisons. The resulting “matches” and “non-matches” are discussed from the standpoint of information value.

The Use of Lycode Powders for the Detection of Erasures

A simple procedure for the detection of “indiarubber” erasures on paper is described. The method depends on the adhesion of Lycode powders to minute traces of grease on the surface of the paper. After use the powders are simply removed by wiping with tissue and the document is thus restored to its original unmarked condition.

Terminology in forensic science.

A review of the literature has been made of terms used to describe samples submitted to forensic science laboratories for examination. A wide variety of terms was found describing similar types of sample. In view of this diversity a unified terminology is recommended.

The Examination of Bloodstains by Laurell Electrophoresis: (Antigen/Antibody Crossed Electrophoresis)

The recently described technique of crossed antigen/antibody electrophoresis has been adapted for studying experimentally prepared bloodstains. Full practical details are given and a discussion of the technique and its potential use in forensic science is presented. Attention is drawn to gross differences in serum protein patterns that may occur in bloodstain extracts and also to clear differences observed between the major haptoglobin variants by this technique.

The Nature of the Process of Identification

A paper presented at the meeting of the Canadian Society of Forensic Science, Ottawa, October, i 962. The paper was read by Dr.C.G. Farmilo.

Estimation of Time Since Intercourse from Acid Phosphatase/UV270 Absorbance Ratios

Acid phosphatase activity and the UV absorbance at 270nm have been measured on extracts from 283 vaginal swabs supplied by volunteer donors. Plots of coital time interval against the logarithm of acid phosphatase activity/UV 270 absorbance ratios have been constructed, and the usefulness of the data for time since intercourse estimations has been tested by means of a declared blind trial. A statistical presentation of the results has also been devised, which if consolidated by more data, would aid the scientist to assess the evidential value of swab analysis.

Forensic Science in the United Kingdom

The types of assistance which the scientist may give to the investigating officer and the courts are defined. Modern techniques are briefly mentioned and their relationships with the crime investigation process outlined. Some problems of the interpretation of scientific evidence and the provision of data banks and computer facilities are discussed. Finally, the monitoring of the performance of forensic science laboratories by the use of Quality Assurance procedures is advocated.

The molecular polymorphism of ABH blood-group substances in human saliva--a scientific enigma?

The alleged existence, by Fiori, of polymorphic forms of ABH blood group substances in human saliva is discussed. Evidence is adduced that these polymorphic forms do not exist but that another phenomenon, antithetical to the Fiori system, does. The implications, and dangers, in the field of crime investigation are indicated.

The Individuality of Tagging Powders—The Lycode System

A system is described which uses dyed Lycopodium spores of various colours, in fixed ratios, to yield tagging powders of high information content. A paper presented at the 6th meeting of the International Association of Forensic Sciences, Edinburgh, 1972. The manuscript of this paper appeared in the International Microform Journal of Legal Medicine (1973 Vol. 8, No. 2, Card 9, Item 42). The powders are the subject of British Patent 1399551 (1972).