THE FATAL SEED OF GRASS

Evening Post, Volume CXIX, Issue 128, 1 June 1935, Page 25

THE FATAL SEED OF GRASS

A grass seed in the turn-ups of a man's trousers, a stray hair, a piece of soil on a criminal's shoe, dirt in the finger nails of a murderer, faint footprints on linoleum, stray fibres from a child's scarf—all these seemingly insignificant things have been the means by which the police have brought criminals to justice. They are mentioned in the "Police Journal" in an article by Captain Athelstan Popkess, Chief Constable of Nottingham, describing the scientific methods used by Nottingham police laboratory in the detection of crime. Some of the most remarkable cases deal with the science of spectography —a system of analysis of substances by light wave length. . Many criminals have been convicted ■by spectograph evidence—which proves scientifically how the dust from a coal-heaver's clothes differs from the dust on a carpenter's coat. Captain Popkess writes:—"We have recently mounted on microscope slides the seed of every kind of grass that grows in Nottinghamshire and surrounding counties. "We are at present mounting the hairs of animals, and to assist to this end we have recently received hairs of every animal in the London Zoo. "We are also mounting soils and commercial dusts1 and fibres. It is a job of one man for several days a week for a couple of years, and even then it will be by no means comprehensive." Captain Popkess describes how these scientific methods resulted in a man being sentenced to seven years' penal servitude for an attack on a child. The man was detained and on his clothes were found fragments of coarse woodland grass and also a

ground ivy leaf, both of which were identical with those growing on the scene of the crime. The crime detection laboratory did valuable service in the Retford murder case, in which Walter Prince, a 32-year-old labourer, was found guilty of strangling Harriet Shaw, aged 21, in some bushes a mile from Retford. Prince's finger-nails were scraped, and the substances found were examined under the miscroscope. These substances, with hair and fibres found on the bushes, and hair on the prisoner's coat identical with that of the dead girl, were all used as evidence against the murderer. "Some thirty breaks-in were perpetrated by somebody who evidently knew his job.' We had no line whatever on which to work. Then one day there was fpund a woman's highheel shoe mark in a garden bed, of which a cast was made. "From Sheffield came descriptions and photographs of a man and woman working together. Theatre and cinema queues were watched, and the man was picked up and followed to a house outside the city boundary, where the woman was also arrested. The heel of a shoe found in the house was a replica of the cast made by the police. The pair had done nearly 200 similar jobs in other parts of the country before being arrested." Footprints on linoleum, however faint, have been successfully taken with a preparation of pyroxylin. The preparation is poured over the footprint and left to dry. It is transparent, and a photographic print can then be made. Work on counterfeit coins, banknotes, and handwriting is also done in the laboratory, where metals and inks are analysed.

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