The man who carried out the Sandy Hook Elementary School massacre apparently called a radio station a year earlier to discuss the 2009 mauling of a Connecticut woman by a chimpanzee.
The caller believed to be Adam Lanza speaks softly on a show on the University of Oregon's campus radio station and blames "civilisation" for the animal's attack.
It would be the first known public recording of Lanza's voice. The 20-year-old man killed 20 children and six adults at the school on December 14, 2012.
A person with the username "Smiggles" describes making the call afterward in a web posting. State police documents refer to instant messages from "Smiggles" as presumably being from the shooter.
A former classmate, Kyle Kromberg, told the New York Daily News that he recognized the voice as Lanza's.
