Peter Henning, Wayne State law professor, was quoted in an article about the dwindling percentages of criminal tax investigations being completed by the Michigan State Police. Henning said tax investigations are a time-consuming and document-intensive process, and that they are not nearly as appealing to an investigator as a homicide, or any other immediate crime. The Michigan State Police completed just nine criminal tax investigations last year, in a state with more than 6 million business and individual tax payers.