Two men detained in the early days of the investigation into the disappearance of NBC Today co-anchor Savannah Guthrie’s mother said they plan to sue the Pima County Sheriff’s Office for wrongful arrest as the high-profile case reaches the six-month mark with no arrests or major breakthroughs.

Nancy Guthrie, 84, disappeared from her Tucson, Arizona, home on Feb. 1. Authorities believe she was kidnapped, but no trace of her has been found despite an extensive investigation with a number of leads, including blood splatter left behind at the scene where she was allegedly taken.