Investigators believe the suspect is still roaming the mountains around Zion National Park based on recent cabin break-ins where food and clothing were taken, Kane County Sheriff's Detective Dathan Chamberlain, who has been assigned full-time to the case, told The Associated Press on Wednesday.
Detectives have alerted Zion rangers and are distributing wanted posters and warning cabin owners to be on the lookout for the man, identified in February as Troy James Knapp based on fingerprints lifted from one cabin and surveillance photos taken outside another.
Authorities say Knapp could be traversing the national park, following rivers, using pay phones, or even riding the park's shuttle buses to stock up on food in a nearby town, said Cindy Purcell, the park's chief ranger.
Knapp's father, Bruce, had little to say when reached by telephone Wednesday at his Moscow, Idaho home.
"If he's doing something criminal, he should turn himself in," Bruce Knapp told the AP.
Authorities say Knapp's family hasn't been helpful in their investigation, and in February they obtained a court order to track phone calls made to his parents.
An arrest warrant issued by Kane County in January charges Knapp with three burglaries and a weapons charge.
While there have been no violent confrontations, authorities fear Knapp is a ticking time bomb. He has left some cabins riddled with bullet holes, defaced religious icons and wrote taunting notes for cabin owners and lawmen. "Hey Sheriff ... Gonna put you in the ground!" one note said, according to court records.
There has been no sighting of Knapp for years, however. Detectives say he lives off the comfort of cabins in winter and retreats with stolen weapons and supplies to makeshift summer camps deep in the forest. They believe he might be on the move now with the warming weather.
According to police and court records, Knapp fell off the radar in 2002 when he apparently left California in violation of his parole for a previous burglary conviction. Records indicate he was charged with theft in 2000 in California, pleaded guilty and was sentenced to two years in prison.
"He went on the run nine years ago," said Bobby Haase, a spokesman for the California Department of Corrections and Rehabilitation.
As a teenager, Knapp was convicted in Michigan of breaking and entering, passing bad checks and unlawful flight from authorities, according to court records in Kalamazoo County.
His most serious offense, an arrest for felony assault in Michigan, was reduced in 1994 to a charge of malicious destruction of property after he agreed to plead guilty.
Back in the mountains east of Cedar City, returning cabin owners say they've seen no sign of him, but they're concerned.
"I'd like to see it all go away," Jud Hendrickson, 62, of nearby St. George, said Wednesday. "My wife is anxious about the whole thing."
Hendrickson plans to return to the area where he keeps a trailer for the Memorial Day weekend.
From the start, the suspect's lore grew in the months and years before authorities say they identified him as Knapp. Theories circulated that he might have been a man on the FBI's Most Wanted list or possibly a castaway from the nearby compounds of the Fundamentalist Church of Jesus Christ of Latter Day Saints, the polygamous sect run by jailed leader Warren Jeffs.
Authorities now have a name, but the suspect remains a ghost.
Hendrickson suspects he's getting help from someone or is finding his way into towns for supplies.
"It's against all laws of human nature for a guy to go five or six years without communication or support from others," he said.