Police are reactive. meaning it was found outside the safeguards. Some would have to spot the fraud separately an alerted the police, which many case are called fake just because it has not moved beyond a witness complaint.
Second, "Gordon protested the runoff results and the Democratic Party threw out 78 of Flott's votes, erasing his margin and making Gordon, who faced no Republican opponent in the general election, the new District 98 representative." That changed the result.
Third, "The clerk's office learned of the assisted-living case after the wife apparently called the Canton Township clerk's office and requested an absentee ballot.
Once the clerk's office staff discovered the requestee's ballot had already been filled out, signed and submitted by her spouse, the case was reported to the attorney general." The fraud vote was cast. It was only because someone tried to vote afterword that the fraud was found.