Extensive experience does not necessarily make policemen better murder investigators

https://www.eurekalert.org/pub_releases/2016-12/uog-eed121316.php

Public Release: 13-Dec-2016
Extensive experience does not necessarily make policemen better murder investigators
University of Gothenburg

Recently graduated Norwegian police officers may perform better in murder cases than investigators with extensive experience. And English murder investigators are far better than their colleagues in Norway, which can be explained by a more systematic approach and clear-cut professionalisation of the detective role in England. This is revealed in a thesis in psychology from The University of Gothenburg.

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In both cases, the British experts performed almost twice as well as the Norwegian group. The majority of the Norwegian investigators became locked into an initial hypothesis about who was guilty and only managed in exceptional cases to create new investigative scenarios even where they were encouraged to do so.

"Norwegian investigators seem to grow increasingly characterised by mental stereotypes the longer they work, while the English specialists show an impressively robust ability to resist this," says Ivar Fahsing.

Education per se set the participants apart. New Norwegian police graduates are educated to a higher level than the English bobbies. The newly trained Norwegian police also succeeded better than their English counterparts.

"This indicates that the bachelor's degree currently obligatory for joining the police in Norway provides a solid foundation upon which to develop investigative expertise," says Ivar Fahsing.

However, all of the test groups showed a tendency to favour hypotheses that involved the perpetration of a crime rather than non-criminal hypotheses such as accident, illness, voluntary departure etc.

"All in all, my thesis shows that it is difficult for investigators, regardless of experience and training, to fully uphold the legal principle 'innocent until proven guilty' deriving inter alia from the European Convention on Human Rights," says Ivar Fahsing.