Besides Koenig, whose body was found in a lake north of Anchorage, authorities have identified only two of Keyes' other victims, Bill and Lorraine Currier of Essex Junction, Vermont.

More clues may come from an illegible, blood-soaked note that was found in Keyes' cell after his suicide. That is being analyzed at the FBI's lab in Quantico, Virginia, Mews said, in hopes of determining what Keyes wrote.

Authorities are asking that anyone who may have information about Keyes get in contact with the FBI at 1-800-CALL-FBI or call their local FBI office.