Link: https://en.wikipedia.org/wiki/Ricky_McCormick's_encrypted_notes

The partially decomposed body of Ricky McCormick was discovered in a field in St. Charles County, Missouri on June 30, 1999. Sheriffs found two garbled hand-written notes – apparently written in secret code – in the victim's pockets, and these were handed over to the FBI for further investigation. Attempts by the FBI's Cryptanalysis and Racketeering Records Unit (CRRU) and the American Cryptogram Association failed to decipher the meanings of those two coded notes, which are listed as one of the CRRU's top unsolved cases. On March 29, 2011, the U.S. Federal Bureau of Investigation issued an appeal for help from the public in obtaining the meaning of the messages.

The two notes are below