Michigan Attorney General Bill Schuette said this week he would look into questionable mortgage documentation filed in the state's Register of Deeds offices, particularly those linked to DocX. The investigation comes after receiving a letter from Bill Bullard, the Oakland County clerk/register of deeds. In the letter, Bullard said he uncovered "a serious pattern of document fraud." Bullard began reviewing his county's own files after viewing a recent "60 Minutes" story on faulty mortgage documentation signed en masse by DocX, a subsidiary of Lender Processing Services (LPS). According to the "60 Minutes" story, several former DocX employees said they signed foreclosure affidavits stating they reviewed files as "Linda Green." So far, he has found five signatures from Linda Green in assignments of mortgages recorded in Oakland County, just north of Detroit, in 2008 and 2009. A spokesperson for LPS did not immediately have a comment. LPS previously said the varying signature styles from its subsidiary resulted from a DocX practice discontinued in 2008. "I have also reviewed numerous other mortgage assignments whose bank officers' signatures vary widely from signature to signature leading to me to suspect forgery," Bullard said in the letter, adding that his investigation into more than 12,000 recorded assignments of mortgages is ongoing. Schuette said other county officials have uncovered suspect signatures as well. He began the process of working with local, state and federal authorities to look into the problem. Since the fall of 2010, Schuette has worked with the other 49 state AGs in their investigation into similar robo-signing and mortgage servicing issues. Settlement negotiations in the case are still ongoing. Write to Jon Prior. Follow him on Twitter @JonAPrior.