remove fales felonie of my cousin Chris Clays

At 21 years old my cousin did a foolish thing, and met a girl at a bar, he believed that she was the age she said she was. He found out two late that she had lied and was under age. Her parents did not place charges but the state of Michigan did. He took a deal and did not get any felonies on his record and did not even have to register in Michigan. Later when he moved to Iowa they put him on a list for 10 years (not because the state wanted to but according to the laws they had to), Then after 10 years they took him off the list. He then moved to FL. with no felonies and a Government Document saying that He should not be on any list of any kind any more. The police of Polk county decided with out looking at the Government Document that he had from Iowa or doing very little detective work at all that he should be on the list and made him a felon for not registering and when he went to court to fight the charge the court would not look at the document and put him under house arrest for 2 years please help him get this off of these false charges and remove this felony off his record and get him off of his house arrest. Thank you.