By the late 1980s Folkvord had earned the nickname "watch dog", as he usually wanted an "independent investigation" into corruption matters. This eventually developed into one of his most well-known public traits. When leading an investigation into a corruption case in 1989, which involved several representatives of the Oslo City Council, he said "It is possible to sweep corruption and other non-essential nonsense out of City Hall. People only need to persist where necessary". Earlier that year, when finding more proof of a so-called corruption scandal, Folkvord asked for assistance from the district attorney urging him to lead an investigation into the matter.