An Illinois woman charged with a Cook County judge in a mortgage fraud case has pleaded guilty to federal mail fraud charges.

Maria Bartko told U.S. District Judge Thomas Durkin she knew what she did was wrong when she entered her plea Friday.

Judge Jessica A. O'Brien is accused of lying and concealing relevant facts from lenders to obtain more than $1.4 million in mortgages. The mortgages were obtained for Chicago investment properties she purchased and sold between 2004 and 2007.

O'Brien is set to stand trial Feb. 5, a case prosecutors say is expected to last several days. O'Brien is now assigned to administrative duties.

Bartko is expected to be called as a witness. Prosecutors say they'll recommend a low sentence if Bartko continues to cooperate with the government.