Blue was working for the department while the FBI investigated him for several civil rights violations that include robbery and kidnapping.
Blue and a co-conspirator were both indicted this week for "injuring, oppressing, threatening and intimidating" suspects in drug cases between January 2014 and July 2018.
WREG found out Blue joined MPD in 1995 and its crime response unit in 2004.
MPD says he was relieved of duty Friday.
"You have to go back and look at the cases and see if Officer Blue signed an affidavit, because if he's the one who swore under oath that he had the facts to the crime, I think you have a really good argument that case should be disposed of," said criminal defense attorney Murray Wells.
He and other attorneys we spoke with say they will review files to determine if Blue was involved in any of their cases.
"You would have to go back and prove he was lying on the stand which is a really difficult thing to do," said Wells. "As that case progresses through a plea or trial, we are going to learn what Officer Blue has been up to and how much he touched and how much it affected."
It's unclear if there are any active cases that Blue worked on.
That's something the district attorney's office is trying to find out.
In a statement, General Amy Weirich wrote, "Cases in which he participated will be evaluated to determine the extent of his involvement. Decisions on how to proceed then will be made on a case by case basis."