MILWAUKEE (WTAQ) - A 13th person was granted immunity from prosecution today in the two-year-old John Doe probe into Governor Scott Walker’s former Milwaukee County aides.

Fran McLaughlin was a spokeswoman for Walker when he was the county executive. She served from 2007 through 2010, when Walker was first elected as governor.

McLaughlin stayed in county government after Walker left – and she’s now the chief spokeswoman for Sheriff David Clarke.

The Milwaukee County John Doe investigation is two years old and still going. Prosecutors use them to secretly gather evidence and testimony which help them decide whether or not to file charges in a particular case.

The names of those getting immunity are the only things required to be public records during John Does.

Five people have been charged in the Walker probe – 3 former county aides, an appointee, and a campaign donor.