An Alaska serial killer admitted to murdering eight people, but authorities suspect there are more victims across the country.

FBI Special Agent Jolene Goeden on Friday put the number of victims at fewer than 12, but acknowledges she doesn't know for sure because Israel Keyes took that information with him when he committed suicide Sunday at an Anchorage jail.

Goeden and Anchorage Police Officer Jeff Bell tell The Associated Press they deduced the number of victims from hours of conversations they had with Keyes.

Three of the eight people Keyes confessed to killing have been identified, but he provided few details about the other five.

The FBI has released a timeline of Keyes' travels over the past decade and is seeking the public's help in finding other potential victims.

Also Friday, FBI agents in Oregon say Keyes admitted to raping -- but not killing -- a young girl on the Deshutes River near Maupin, Ore., between 1996 and 1998 after separating her from a group of friends.
   
Agents say the woman would now be in her late 20s or 30s. There are no police records of the rape. Anyone with information is asked to call 1-800-CALL-FBI.