Sex determination with the head of the radius

Analysis of a sample of 1108 radii corresponding to 567 black and white North Americans in the Terry Collection at the Smithsonian Institution demonstrates that the diameter of the radial head is an accurate sex discriminator for human remains. A simple "radial-head method" of sex determination consists of measuring the maximum and minimum diameters of the head and comparing such measurements with the test cutoff points. The subject is female when the maximum radial head diameter (either left or right) is less than or equal to 21 mm, and male when the maximum diameter (either left or right) is greater than or equal to 24 mm. The same decisions apply to the minimum diameters of 20 mm or less and 23 mm or more, respectively. When the maximum diameter is 23 mm or the minimum is 22 mm, the subject is more likely male; when the maximum diameter is 22 mm or the minimum is 21 mm, the subject is more likely female. The sample frequency of any one of these latter diameters is never more than 16%. Cross-validation of the method with a sample of 50 pairs of radii of the Terry Collection, different from the original specimens, resulted in 92% sexing accuracy when using the left radius singly, 94% accuracy when using the right radius singly, and 96% accuracy when using both radii jointly.     

Behavior of animal blood in blood typing systems. Isoelectric focusing of erythrocyte acid phosphatase and phosphoglucomutase

Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.     

The cutaneous ink sign: a tipoff to suicide or suicide notes

The presence of smeared or unsmeared ink on the skin resulting from the writing process has been observed in a number of suicide victims who have left suicide notes. The authors report a case of a palmar "cutaneous ink sign" and discuss its forensic science import.