Riverside County District Attorney Rod Pacheco says Hillman left home when investigators served a search warrant for the property more than two weeks ago. He has been a fugitive ever since.
Oyler was convicted of five counts of first degree murder, 20 counts of arson and 17 counts of using an incendiary device to commit arson in the Esperanza Fire near Cabazon in October 2006. Five firefighters were killed when flames swept over an isolated hilltop home they were defending.
The Associated Press contributed to this story.