MILWAUKEE (AP) -- Democrats are lashing out at Republican Gov. Scott Walker, saying newly released emails show he clearly engaged in illegal campaigning while he was Milwaukee County executive.

Milwaukee County Assistant District Attorney Bruce Landgraf revealed an email in court on Monday that indicates Walker ordered top aides on his gubernatorial campaign to coordinate on media strategy with his county staff at 8 a.m. daily. Prosecutors seized the emails in a secret investigation into Walker's county office.

Walker's campaign has said elected officials' campaigns and offices routinely communicate. But the state Democratic Party issued a release Tuesday saying there's no doubt Walker himself was involved in criminal activity.

Walker has not been charged with any wrongdoing in the investigation, which has now stretched on for more than two years.