Public Release: 

Extensive experience does not necessarily make policemen better murder investigators

University of Gothenburg


IMAGE: Ivar Fahsing. view more

Credit: The 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.

Image of Ivar FahsingIn the short story The Boscombe Valley Mystery Sherlock Holmes says: "There is nothing more deceptive than an obvious fact." Even in real-world criminal investigations, it is a fundamental but demanding skill and ability of the police at the start of a criminal investigation to identify all the potential scenarios, follow-up obvious clues and resist the pressure to sharpen the focus too early in the investigation.

"If you are incapable of that, critical clues may quickly disappear and the investigation can end up in a blind alley or in the worst case lead to a wrongful conviction," says Ivar Fahsing, author of the thesis.

He wanted to find out if the system in Norway was as good as that in England for developing expertise in the investigation of serious crimes. A working method was introduced in England and Wales in 2005 that sought to standardise the investigative process. And in order to investigate serious violent crimes, the police also have to gain certification in a programme known as Professionalising Investigation Programme. Other than England and Wales, no countries currently have a corresponding system.

Ivar Fahsing carried out tests with sixty Norwegian and sixty English police officers. The groups included both recently graduated police officers and experienced murder investigators. The participants had to examine two fictitious cases; one where a Kurdish girl has disappeared and one where a woman is found murdered the day after her husband left home and checked into a hotel.

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.


For further information: Ivar A. Fahsing, telephone: +47 9222 5533, email:

Title of thesis: The Making of an Expert Detective: Thinking and Deciding in Criminal Investigations

More about the thesis at:

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.