A primer on Wisconsin court ending Walker campaign probe

FILE - In this July 13, 2015 file photo, Wisconsin Gov. Scott Walker speaks to supporters as he announces he is running for the 2016 Republican presidential nomination at the Waukesha County Expo Center in Waukesha, Wis. The Wisconsin Supreme Court on Thursday ended a secret investigation into whether Republican Gov. Scott Walker's campaign illegally coordinated with conservative groups in winning his 2012 recall election. (AP Photo/Morry Gash) FILE - In this July 13, 2015 file photo, Wisconsin Gov. Scott Walker speaks to supporters as he announces he is running for the 2016 Republican presidential nomination at the Waukesha County Expo Center in Waukesha, Wis. The Wisconsin Supreme Court on Thursday ended a secret investigation into whether Republican Gov. Scott Walker's campaign illegally coordinated with conservative groups in winning his 2012 recall election. (AP Photo/Morry Gash)

By Associated Press July 16, 2015 4 min read

MADISON, Wis. (AP) – The Wisconsin Supreme Court’s decision to end a so-called John Doe investigation of Gov. Scott Walker’s 2012 recall campaign clears a potential obstacle in his Republican presidential bid and has far-reaching implications for the state’s campaign finance laws.

Here are some questions and answers about the probe and the effects of the high court’s ruling on Thursday:

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WHAT IS A JOHN DOE INVESTIGATION?

A John Doe probe is Wisconsin’s equivalent of a grand jury investigation. The goal is to ascertain whether a crime has been committed. The investigation is overseen by a judge, and witnesses can be compelled to testify in secret. Information that emerges is kept secret.