SCIENCE and the CRIMINAL

Auckland Star, Volume LXXI, Issue 297, 14 December 1940, Page 4 (Supplement)

SCIENCE and the CRIMINAL

THE discovery in 1900 that human blood is divisible according to its agglutination reaction into four groups was a further development in the identification of bloodstains. A sample of blood cannot be attributed to any one person, but the agglutination test can supply irrefutable negative evidence— for instance, if a murder victiru belongs to No. 1 blood group, a stain of Group IV. blood on a suspect s clothing is definitely not the victim's blood. The Friedson Murder The grouping tost. was described by tho Homo < Klii'o armlyst <l)r. I! or ho Lynch) during Hie trial Va I!>:>2 of Mn urioo. Friedman, charged with tho. nninlo.r of Annottc Friedson. The test is applied liy mixing a human sorum of a known group with a snline solution of the; bloodr-tain to lie examined. Blood of Group I. will coagulate with Group 11. and (iroup JIT. but Group 11. onlv with Group 111., while Group IV. agglutinate.* with neither J. nor 11. The Home Office analyst applied this test to the blood of Annette Friedson, who. on January 20, 19:52, in Fore. Street, in London, wan fatally attacked and killed with a razor by an assailant who

Blood-stained Clues

By F. Reeder

escaped. Her blood was shown to belong to (iroup 1., and the Home Office analyst went on to say that an average of only throe | mm - sons in a hundred belonged to tliis blood group. I lie same to»«t had bo.cn applied, the analyst went on, to the blood on a razor found on the Ic,p of the bus and believed to be the weapon with which the crime was committed. This blood also belonged to < ■ roup X. I his diil not prove eonelui-ivelv, of course, that, it was Annette Friodson's blood on the razor and that this was the weapon with which she had been killed, but, it established a very strong presumption. Blood of the Dog I he fact that if the test, animal (commonly a rabbit) is injected wit h dog's blood, the serum will react only to the blood of a dog, or of some, closely allied animal. A wolf, for instance, increase* the scope of the Bordet test. The reaction in this form was used some years ago in the solution of a French crime, in which the murderer had killed also his victim s do?. No stains of human blood were, found on tho suspect's clothes, but the stains were shown to be dog's blood.

Scientists still hope, possibly by some refinement of the Bordet Reactior, that the}* will be able to go further than group classification and be able to identify positively the blood of any given person. As many murder suspects claim that blood on their clothing is their own, such a test would be of inestimable value. The eminent French medico-legal expert Dervieux has claimed that after injecting a rabbit with human sperm instead of blood, the serum gave a positive test both for human blood and sperm, and showed a more copious preeip't;ite with the blood or sperm of the individual from whom tin: injection was obtained than with that of other persons. This has yet to be accepted, however, the difficulty !>eing hi judging the amount of precipitate. It will be an interesting day, too, when the defence puts forward that the blood on a 6U3|K.'ct's clothes is not that of a human being but of one of the anthropoid a[K?R, since the blood of these gives, t hough to a lesser decree, the Bordet .Reaction for human blood. So far, however, t-hU has been of more importance to the biologist, as supporting the theory of evolution, than to the criminologist. One of the beauties of the test is that only small samples of blood are needed, and the test is good for samples up to nine years old. The criminal commonly wipes the blade of hie knife or axe, but sufficient blood to he tested will linger in disregarded crevices. Under the Microscope Exp: rt ex*'initiation of blood stains may reveal even more than these facts. Quite commonly, a suspect attributes blood stains on his clothes to bleeding from his own nose. His story is confirmed if. under the microscope, the typi<al small hairs or epithelial cells from the nasal lining are discovered, though their a.bseme does not necessarily contradict him. Coagulating blood will, under favourable circumstances, record impressions with great clearness, and fingerprints in blood stains have in several cases proved of vital importance. <?#ie German case is something of a classic in its line. The victim was savagely wounded and covered in blood, and the curious shape of a stain on his' shirt, near the shoulder, at first escaped notice. Examined through a lens, however, th'l6 patch showed clearly the weave of cloth, and from its shape and position the investigators decided that the murderer had knelt with one knee on his victim. When a suspect was arrested, no blood stains were found on his clothes, but a pair of his trousers had been washed since the crime. The blood stain was an exact print of the cloth of tlie-ve trousers and proved thus to be t\ most, imj»>rianL piece of evidence against him. r i he shape of a. drop of blood can also <<•11 the investigator something. A drop falling on the floor from a person who is jierfectlv atill makes a circular stain, often surrounded by tiny drops if it has fallen from some ' height. Blond dripping from a. |km*soii walking makes pearshaj>ed [m>«ls on the floor, the thin end of the pool |K)inting the direction the person was going.