A newly uncovered word puzzle written by infamous serial killer Dennis Rader, known as BTK, spells the name of a missing Oklahoma girl and the location she was last seen, authorities said.

The Osage County Sheriffs Office received the annotated puzzle in a package last month, Sheriff Eddie Virden told KFOR , highlighting words that can be connected to the disappearance of 16-year-old cheerleader Cynthia Cindy Dawn Kinney. She was last seen in June of 1976, leaving the laundromat owned by her family in Pawhuska, Oklahoma.

Rader originally sent the puzzle to a Kansas news station in 2004. It has since been posted elsewhere, including a website devoted to the Zodiac Killers ciphers , with different solutions.