The document, which Fox News said appeared to be a leaked draft copy of the consent decree, lead mayoral candidate Lori Lightfoot to call on Mayor Rahm Emanuel to investigate who released them.
Lightfoot headed up Chicago's Police Accountability Task Force.
The Chicago Police Department has been under state and federal scrutiny since video showing the 2014 police shooting of McDonald was released.
A Department of Justice investigation found that CPD officers have engaged in a pattern of using unreasonable force, including deadly force, for years.
In 2017, attorney general Lisa Madigan sued the City of Chicago to force officials to sign a consent decree to institute reforms.
Emanuel's office said it has been partnering with the Attorney General's office on the consent decree for the better part of a year. The negotiations are ongoing.