On Tuesday, the Pima County Sheriff’s Office said in a statement that it was “aware of reports circulating about possible ransom note(s)” circulating about Ms. Guthrie’s disappearance after the celebrity news site TMZ said that it had received a ransom note on Tuesday demanding a Bitcoin payment. An anchor for KOLD, the CBS television affiliate in Tucson, said the station had also received a ransom note. It was not clear if the messages received by the newsrooms were actually sent by anyone involved in the abduction of Ms. Guthrie.