What's happened in probe to date

The John Doe probe by the Milwaukee County district attorney's office has produced one conviction of a major campaign donor to Gov. Scott Walker and criminal charges against three of his former county office aides and a Walker appointee. Two of those charged are among Walker's long-serving aides.

William Gardner, a railroad executive, was sentenced to two years of probation in July after pleading guilty to two felonies for exceeding campaign contribution limits to Walker's campaign and laundering additional campaign contributions through employees and associates.

On Jan. 5, prosecutors charged Timothy Russell, former Walker deputy chief of staff, and former county veterans official Kevin Kavanaugh with stealing a total of $60,000 in donations intended for Operation Freedom, the Walker-initiated, county-run military appreciation picnic. Also on Jan. 5, Russell's longtime partner, Brian Pierick, was charged with two felony counts of child enticement.

What happened Thursday

Prosecutors charged two former Walker aides at the county with illegally doing extensive political work while being paid by taxpayers to do county jobs. Prosecutors also alleged that a small group of Walker's top aides created a secret Internet email network to allow them to communicate about county and campaign work.

Former Walker deputy chief of staff Kelly Rindfleisch was charged with four felony counts of misconduct in office, accused of working for then-Rep. Brett Davis' 2010 campaign for lieutenant governor while on the county clock. Davis, who lost in the Republican primary, is now Walker's state Medicaid director.

Darlene Wink, Walker's former constituent services coordinator, is facing two misdemeanor counts for using county resources to raise money for Walker's 2010 gubernatorial bid.

What's next

Prosecutors continue to investigate several angles, including whether favoritism was shown during a competition in 2010 to house the county's Department on Aging in private office space.

Kavanaugh is due in court Monday for a scheduling conference.

Russell is to be arraigned on Feb. 16.

Rindfleisch was ordered to make an initial court appearance Feb. 22.

- Dave Umhoefer