Schimel argued Halbrooks, who was a witness in the first John Doe investigation into Gov. Scott Walker and his associates during his time as Milwaukee County Executive, should recuse himself from any involvement related to the most recent DOJ investigation. The first John Doe investigation was used as a basis for the second secret probe and, Schimel argued, a third investigation DOJ refers to as "John Doe III."

The "previously unknown and secret investigation into a broad range of Wisconsin Republicans" was uncovered during the DOJ investigation of the Guardian leak.

According to the report, more than 500,000 emails and private messages were found on hard drives in the basement of the former GAB in boxes labeled "Shane Falk," the name of a former GAB attorney. Also according to the report, thousands of private emails and instant message conversations from Wisconsin Republicans were held on GAB servers in folders marked "Opposition Research."

Halbrooks and McCallum disputed that element of the report, arguing the "Opposition Research" file was a piece of "illegally seized data" and not a document created by a GAB employee.