As district attorney, Chisholm garnered notoriety for two inquiries he led into staff misconduct and potential campaign finance violations surrounding Wisconsin Governor Scott Walker.
Chisholm received national attention surrounding his enactment of progressive justice reform policies in Milwaukee County, including criticism in light of the Waukesha Christmas parade attack.
In 1994, Chisholm graduated from the University of Wisconsin Law School and joined the office of Milwaukee County District Attorney E. Michael McCann as a misdemeanor prosecutor.
[citation needed] In 1999, McCann appointed Chisholm as supervising attorney of the Firearms Enforcement Unit, which prosecuted high-profile cases involving organized crime, large-scale drug trafficking, and non-fatal shootings.
[3] In this position, Chisholm prosecuted millionaire marijuana dealer Kenneth L. Green and members of Jamaican and Latin Kings organized crime outfits.
[3][4] As supervising attorney, Chisholm was highly regarded by law enforcement officials for his skill and successful track record in prosecuting gun crime.
[9] As district attorney, Chisholm established a public integrity unit, resulting in the prosecution of Milwaukee alderman Michael McGee, Jr., who was later convicted of federal crimes including bribery and extortion.
[14] Chisholm investigated and prosecuted violent felons, including preacher and organized crime figure Michael Lock and serial killer Walter E. Ellis, known as the "North Side Strangler" who targeted prostitutes in Milwaukee for two decades.
[20] In 2010, Chisholm conducted a confidential "John Doe" investigation into financial and political misconduct on the part of staff and campaign supporters of politician Scott Walker, then the Milwaukee County Executive and a successful candidate for Governor of Wisconsin.
[citation needed] Eric O'Keefe, among others, sued and filed complaints against Chisholm, in both federal and Wisconsin courts, alleging the commission of civil rights violations during the course of the investigation.
[26] Following the federal court ruling, conservative activist Chris Kliesmet requested that a Dodge County prosecutor and circuit judge probe Chisholm's conduct during the second investigation.
Justice Michael Gableman, writing for the majority, stated, "It is utterly clear that the prosecutor has employed theories of law that do not exist in order to investigate citizens who were wholly innocent of any wrongdoing.