Bombshell ruling in John Doe investigation

MILWAUKEE-A federal judge has shut down the investigation involving a long running John Doe Investigation, Wisconsin Governor Scott Walker and possible illegal campaign activity during the recall two years ago.

Prosecutors had been looking into whether there was any illegal coordination between a number of conservative groups and Scott Walker's campaign in the months leading up the recall, which Walker survived.

One of those groups,  The Wisconsin Club for Growth, then sued to get the probe stopped.

Now Federal Judge Rudolf Randa has done just that.

Randa says the type of activity prosecutors were looking into is protected free speech and that prosecutors must cease all activities related to that investigation, return all property seized and permanently destroy all copies of information and other materials.

One legal insider tells CBS 58's Paul Piaskoski he's not surprised by the ruling given Randa's reputation as a conservative judge. It comes less than a week after Lynn Adlemann, a more liberal leaning federal judge, struck down Scott Walker's voter i.d. law.