MINNEAPOLIS — Prosecutors have thrown out rape charges filed against a convicted sex offender accused of attacking an employee at a Twin Cites amusement park in 2018 after his attorney discovered investigators mixed up the DNA tests.

Twenty-seven-year-old Austin Jeffrey Jones was scheduled to stand trial next week on two charges related to the alleged assault at Valleyfair in Shakopee.

A defense review of the Minnesota Bureau of Criminal Apprehension tests showed the alleged victim’s belt buckle had Jones’ DNA on it but not her own DNA, and the front of Jones’ underwear had DNA from the alleged victim but none of his own.

The BCA said in a statement that the samples were inadvertently switched during DNA testing. The case was dropped on Tuesday, although the BCA said it will continue to work on the case.