Afaik, Swedish police don't take bribes and generally don't commit criminal acts. At least not if compared with most other countries.
The main problem with Sweden is that the police is trusted to drink coffee instead of working. :-)
(That was a simplification, the Swedish police seems to mainly have organisational issues. The Finnish police is one of the most trusted societal functions there. I have never understood why a Swedish government won't head hunt top level Finnish police and fire the locals... Just the threat ought to be enough.)
The point is that people have relatively good relationship with police in many countries -- as nice as Sweden is, it doesn't appear in the top 10. The very good standard of Scandinavia is common.
Research does not seem to bear this out. See eg this Gallup study:
http://www.gallup.com/poll/102346/many-world-citizens-trust-...
Of the top 10 "public trusts the police", only 1 or 2 are Scandinavian countries (definitions vary whether Finland is part of Scandinavia).