RUAWARO DEATHS

Ashburton Guardian, Volume 54, Issue 91, 27 January 1934, Page 3

RUAWARO DEATHS

EVIDENCE BY EXPERTS. STUDY BY MEANS OF CAMERA. KNIFE MARKS ON WOOD. (Per Press Association). AUCKLAND, January^. Evidence by experts occupiecT the Court to-day in the hearing or' the case against William Alfred Bayly. Dennis Brown, Doctor of Philosophy of the University of Bristol, and at present acting-Professor of Physics at the Auckland University, said that on November 20 he inspected a piece of timber (produced) at the Auckland police station. . He also was shown a knife, and later took_ photographs of the cutting edge of the knife and of cuts on the piece of timber. They were microscopic photographs. He visited Bayly’s cowshed later and saw an upright piece of timber (produced) supporting the roof. Part of the surface had been whittled away, the cut portion being about two feet from the floor of the shed. The cut portion appeared to have been rubbed over with oil or grease. He judged the cut to be recent because of the absence or dirt accumulation compared with other parts of the wood. Later he took a micro-photograph of the cut portion. Witness produced mounted copies showing a series of eight photographs of two pieces of wood. Photograph No. 1 was a micro-photograph of the ridges on the cut surface on. a piece of wood from Lakey’s implement shed. The j’idges were evidently due to imperfections on the edge of the knife making them. He had marked lines from 1 to S' on No. 1. The marks were slight ridges in relief on the wood, with the exception of No. 4, which was a groove in the wood. The photograph was magnified 8£ times. No. 2 was a micro-photograpn of a portion of the cut surface of a post from the separator room. This showed a number of parallel lines, evidently due to imperfections in the edge of the knife making them. Mr Meredith: What is the nature of those?—They are in this case grooves ploughed into the wood. Were they made at the same time? j think they were made at the same time. I infer that the edge of the knife had a number of turns on it, and as it moved it made parallel grooves in the wood. What do you say about the two pieces of wood?—I noticed that the • complex pattern of the lines on the first piece of wood was repeated on the second piece. I measured them up and found the spacing of the lines was the same in both patterns. J. first measured them by means of a microscope on the photograph. I then tried to match the two patterns together by joining the two photographs, but 1 found that the second photograph was slightly smaller in scale to fit the flirt photograph. I formed the conclusion that this was due to the second cut bein" made with a knife moving on a slant”. 1 have made numerous experiments with knife marks on wood ancl i find that if a knife leaves a pronounced ridge on a piece of wood tneie is a corresponding groove on the shaving taken off the wood, but if the lnnfe is turned over and a cut made in the other direction the ridge is on the shaving and the groove is on the woo.d. The reason for that is what . I* a newly-made notch is due to the edge of the knife being turned back so as to form a burr. r You have illustrated that on one ot your photos?—Yes, that is to show tnat either ridges or grooves can c made by the same notches on tin knife. This was the test knite.

Degree of Improbability. Have you considered the question of chances regarding tne grouping o J on tne two pieces ot wood t— 1 es, i started my calculations by . measuring tno lines on tne lirst test piece or timfev Unci teen tne second. 1 measured tne centres of tne lines l tnen apphect an appropriate analysis, i found tnat tne liKcnnood ot tins particular oroupmg or lines being dvitercnt nas a ess man one m a million. Assuming tnat one was done \utli a- Kill re, wmit was tne otlier one: —tne only possible conclusion is tnat both cuts were done witn tne same> Jam e vVitness went on to say tliat tie portion near tne Handle or tne kiuxe was also piiotograpneu witn a magmncation or 8£ ammeters, winch he nad previously used, in pnotograp ung tne tiuru piece ot woou ne tried juxtaposing tnat against tne pnotograpn (exmbit 15). tie found definite correspondence between tiio notches on the mule and tlie cuts in the wood Witness said he rc-piiotograpned portion of tne hrst piece of wood so as to bring out the new marks more clearly. lie tried placing Ins photograph or the ridges of steei against the parallel marks on tne wood. He found tnat tne spacing of the steel marks was the same as tne photograph of wood marks, borne of tlie mams on the wood were faintly double, no formed the opinion tnat the marks on the wood were not only made by some milled insti llment, but tnat they were formed by steel of that particular type. Guns and Cartridges Tests. You have aho made an examination of the cartridges?-—Yes. On December 6 I examined certain rifles handed to me by Detective Sneddon. The first was a .22 calibre 1902 Winchester, and the second' was a Spadau, also .22. 1 fired cartridges from each rifle. I kept the cartridges, and that day I microphotographed the cartridges from each of the guns. , /On December 7 did Detective Snedden bring ycu another cartridge - Y'es, a .22. ‘While lie was there I made microphotographs under the. same conditions of magnification and lighting as I used for the previous cartridges. I have also photographed the same cartridge on December 21 in Auckland and on January' 6 and 7 in Wellington. Detective Snedden was there on each occasion, and in Wellington a photograph was taken in co-operation with Senior-Sergeant Dinni'e. We also photographed the striker pin of the Winchester. I have a series of photographs numbered one to eight showing the result *of my investigations. Mr Meredith: What are the striker marks on the shell handed to you by Snedden and on the shell from che rifle (exhibit 20)? Dr. Brown: The .striker mark on the shell handed to me by Snedden had an cbling shape, but the bottom edge had an angle of about 14 degrees. Be-

fore I photographed the shell (exhibit 70) I had to remove a quanity of dirt which I. washed out with other. As a result of the various shells shown in the photographs, can you give an ©pinion whether Exhibit 70 shell was fired from the Span dan rifle? T think there is no question, of it being fired from that ride, ns the striker marks were totally different. I am definitely of opinion that shell Exhibit <0 was fired from, the Winchester rifle.