Age Of Bloodstains Research Articles

The use of remission analysis for direct colorimetric determination of age of blood stains (author's transl)

A review is given of the conventional methods of determining the age of blood stains by forensic examination of trace evidence. Detailed analysis of the samples in several steps, which destroyed the traces, and the widely differing results do not appear satisfactory with regard to their use in forensic investigations. Considering the change in color with increasing age the three coloric parameters (chroma, hue, and value of the blood stain) can yield exact numerical measurements which allow to draw relatively reliable conclusions as to the age of the blood stain. Of the three colorimetric methods, based on equalization, three regions, and spectral analysis, respectively, only the last may be considered really satisfactory and up to the requirements of forensic medicine. It has the additional advantage of being independent of the visual acuity of the examiner and of the type and quality of the source of illumination. The aging of freshly taken venous blood, which has been deposited on filter paper or linen, can last up to 33 days, either in the dark or in day light, with due regard to temperature and humidity. The spectrophotometric color measurements taken place on the immediate surface of the blood stain in the range of the visual spectrum between 400 and 600 nm. The continuously drawn spectral curves are then subject to remission analysis the first step. The second step consists in a mathematical computer analysis of color valence measurements.

3.8. Estimating the age of bloodstains by measuring enzymic activities

3.8. Estimating the age of bloodstains by measuring enzymic activities

The Detection of Y Chromosomes in Bloodstains—A Reevaluation

A method has been described for detecting Y chromosomes in the leukocytes of human bloodstains prepared on a variety of substrates. The factors that influence the proportion of chromosomes exhibiting a Y spot (the Y cell index) in a bloodstain are considered, including the subjective nature of assessment of the Y chromosome fluorescence, the substrate, and the age of bloodstain. In contrast to previous workers no decay in Y cell index with the age of the stain was observed. The results of a blind trial involving stains derived from case work, where from other evidence there was no doubt as to the sex of the donor, are presented. Sixty-five percent of the male bloodstains were correctly identified and no females were wrongly reported as male.

�ber die Eignung spektralanalytischer Methoden zur Bestimmung des Blutfleckenalters

The spectrophotometric methods of Kind et al. and Kleihauer et al. were checked by more than 900 experiments on 85 blood stains on different material (cotton, nyltest and paper) from native and citrate blood, aged at room temperature up to 5 years. As a result, the variation of values within one age-group exceeded the differences between the values of samples of different age. Therefore, both methods are thought to be unsuitable for the estimation of blood stain age in practical forensic medicine, although the general trend described by the above authors could be confirmed.

Determination of the Age of Bloodstains Using Immunoelectrophoresis

The technique of immunoelectrophoresis was used to determine the age of bloodstains. The immunoelectrophoretic patterns (IEP) of bloodstains ranging from 15 days to one year old were obtained by the use of high titer anti-whole human serum. The IEPs revealed gradual disappearance of beta-globulins and gamma-globulin with increase in the age of bloodstains. A comparative study of the IEP of normal human serum with those of the experimental bloodstains showed the absence of some of the corresponding proteins. The absence of a particular serum protein in the IEP of a given bloodstain will indicate the age of that bloodstain.

The estimation of blood stain age from the spectrophotometric properties of ammoniacal blood stain extracts

The visible absorption spectra of a series of blood stains up to 15 years old have been examined and found to vary in a regular manner with age. A quantity called the “ α s ratio” (analogues to the a ratio of Kind et al., Forens. Sci., 1 (1972) 27) has been derived and calculated for all blood stains examined. It is suggested that this parameter can give a useful indication of blood stain age up to periods of 10–15 years after stain formation. The ammoniacal extract used for the determination can also be used for determination of the ABO blood group by the method of Kind and Cleevely.