A new computer-assisted possibility for evaluating the evidence value of textile fiber traces

This paper deals with the possibility of coding synthetic textile fibers. Using a small data bank the efficiency of a computer aided data search is demonstrated. It is intended to build up a large collection of textile fibers and to determine at least approximately the frequency of a certain fiber type. If this can be achieved the forensic scientist who has to examine textile fibers in case work will be able for the first time to answer the question about the frequency of an incriminating fiber, a question which is often asked in court.     

Isotachophoretic analysis of bloodstains: differentiation of human, menstrual, bovine, and ovine bloods

Isotachophoresis, a technique to separate components by constant current electrophoresis, was used to differentiate between bloodstains of male, female, menstrual, bovine, and ovine bloods on cotton cloth and filter paper. Bloodstain analysis by isotachophoresis of stains from male and female subjects showed identical cationic patterns, but gave different profiles in the anionic system. Plasma had one extra peak in the anionic system when compared to the profile of serum. This extra peak is due to the presence of fibrinogen in plasma. Some hemoglobin peaks overlapped with serum protein peaks, but these could be identified by comparisons at lower concentrations. Menstrual blood had a much different pattern than normal human blood as was expected since many more compounds are found in menstrual blood than in normally circulating blood. Human, bovine, and ovine bloodstains showed different profiles both in the cationic and anionic systems. These results indicate that isotachophoresis can be used for the rapid and simple analysis of bloodstains to differentiate reliably human male, female, and menstrual blood and also to distinguish human bloodstains from those of cattle or sheep.     

Death by peroral ingestion of soluble glass (sodium silicate)

The intake of 0.51 of water glass (sodium metasilicate; colloid pH 12.5) led to death within 1-1.5 h. Autopsy revealed alkali burns of the stomach mucosa. The stomach contained a small amount of liquid with a pH of 11.5. Histologically, numerous bronchioles and alveoles were filled with amorphous material. This material was chemically proved to be condensed water glass. The obstruction of large parts of the lungs by water glass led to an inhibition of alveolar gas diffusion, which may have been the cause of death. The transformation of the water glass from liquid to solid occurred in the lungs by means of the carbonic acid of expiration air. This was made possible because the pH of water glass had been changed by gastric secretions from 12.5 to 11.5. Water glass starts to solidify around pH 11.4-11.3.     

Determination of phenotypes of salivary amylase in liquid saliva and saliva stains

An isoelectric focusing method is described for typing salivary amylase in liquid saliva and saliva stains. The estimated gene frequencies in a British population, calculated on the basis of three alleles operating at a single locus, were Amy 1, 0.909; Amy 2, 0.065; Amy 3, 0.026. This system may be useful in forensic investigations.     

Hanging: suicide or homicide?

Death by Hanging: Suicide or Homicide. Six cases of homicidal hanging and murder presented as suicidal hanging are recorded. Suspension followed strangulation by ligature or throttling and head injuries in 4 cases. Distinction between homicide and suicide was easy in 5 cases: two of the perpetrators gave themselves up to the police, one committed suicide immediately after he had hanged his 15 year old daughter; in two cases tracks of blood, heavy injuries of the victims, and traces of robbery were obvious. Unless the victim is an infant or an adult person incapacitated by drink, disease, or drugs, or unless there are several assailants murder is difficult to accomplish. Distinction between murder and suicide may be impossible by an examination of the body alone. Detailed investigation of the scene, reconstruction of the position of the suspended body, examination of the rope, the knots, the direction of the fibres on the rope may serve to discover homicidal hanging. - Compared to suicidal hanging homicide has a frequency of about 1% in our autopsy material. However, we cannot estimate the number of obscure cases.