‘Smell bank’ helps nab criminals

Press, 12 August 1989, Page 16

‘Smell bank’ helps nab criminals

NZPA-Reuter Rotterdam A police sergeant, Jan de Bruin, proudly displays his collection of glass jars, each containing the scent of a robber, a rapist or a killer. The. scents, extracted from objects on the scene of a crime or human skin, could help Rotterdam’s police dogs sniff out some of the city’s most dangerous criminals. In his new “smell bank,” the first of its kind in the West, Sergeant de Bruin already has about 40 samples which he can preserve for at least three years. He plans to build the collection, which opened two months ago, to some 300 samples, providing Rotterdam police with a unique addition to their criminal files. “Everybody has a different smell that a dog.

can recognise,”'said Sergeant de Bruin, aged 48, who has devoted the last 12 years to perfecting the science of collecting and storing human odours. "People said I was crazy trying to invent such a system,” said Sergeant de Bruin, technical director of the Rotterdam police dog unit. Scientists are impressed by Sergeant de Bruin’s work, which they say could provide vital clues for criminal investigations. Other Dutch police forces are envious of Rotterdam’s 1.5 million guilder (SI.2M) smell bank, while canine experts in other European countries and the United States are intrigued by his methods. When a serious crime, such as a murder or bank robbery, occurs in Rotter-

dam, Sergeant de Bruin is immediately called to the scene with his home-made scent extraction kit. He wraps any article bearing traces of the criminal’s personal odour in a sterilised cotton cloth and places it in a large plastic ventilation box, equipped with an electric fan. As air blows through the box, scent molecules from the object evaporate and are absorbed by the cotton. After 20 minutes the cloth is transferred to an airtight storage jar, labelled with the date and place of the crime, and stored on wooden shelves at Rotterdam police dog centre, in a room especially assigned for Sergeant de Bruin’s collection. “This sample was taken from the glove of a bank robber,” Sergeant de

Bruin told Reuters, pointing to one of the jars, the sort more commonly used for bottling fruit and vegetables. Another sample came from a cigarette lighter, carelessly dropped by a murderer as he fled. “The whole human body is a source of odours. We leave behind scent molecules wherever we go,” Sergeant de Bruin said, noting he also gathered odour traces directly from human skin. When main crime suspects in Rotterdam are arrested, they are not only photographed and fingerprinted on arrival at a police station, but have to provide a scent sample, by holding one of Sergeant de Bruin’s special cloths for five minutes.

In his experiments, dogs have accurately identified people from a

scent sample taken three years previously, but Sergeant de Bruin believes the specimens could last much longer. "De Bruin’s techniques are quite new and could be very helpful to police,” said chemist Jan Schaefer, an odour specialist at the TNO private research institute in Zeist, who advised Ser-, geant de Bruin on his research. The police have always used trained sniffer dogs to help them track down or identify criminals using the scent of an object belonging to the culprit. “A dog lives in a world of smells. It uses its nose like we use our eyes,” said Mr Schaefer, noting a dog could detect some smells up to a million times better than humans. But he said only highly trained dogs could match

a human odour to its owner, and even the most skilled animals made mistakes if badly handled. The most commonly used police identification test, when a dog selects a culprit from a parade of suspects, was unreliable because humans under stress emit different body odours. “I know of one murder case when the wrong man was convicted after being falsely identified by a dog,” Mr Schaefer said. It was such mistakes that spurred Sergeant de Bruin, who has worked with dogs for over 30 years, to devise more scientific ways of putting his canine colleagues to work. Besides creating his smell bank, Sergeant de Bruin introduced more sophisticated detection tests. Instead of a row of

people, he presents the dog with a row of glass jars containing cloth odour samples, taken earlier from participants in the test. The secret to successful odour preservation, Sergeant de Bruin claims, lies in the quality of his cloths, 30cm squares of absorbent cotton cloth from Britain. The pieces are soaked for six days in sterilising chemicals to remove all foreign odours, then dried in an oven and kept in sealed plastic bags. Sergeant de Bruin said his cloths were more effective than those used by the police in Hungary, the only other country where the police have started to store human smells. “The Hungarians use nappies to collect the odours which doesn’t work as well,” he said.