Authorities returned Thursday to the sprawling Florida wildlife refuge where they have been searching for Brian Laundrie, who is wanted for questioning in the disappearance of his fiancée, Gabby Petito, whose death was ruled a homicide. But Laundrie is likely to have fled the state and may have had help, experts in missing persons cases said. "It seems unlikely that he's still in that reserve. They did not find any trace of him so far. It's been weeks," said former FBI agent Bryanna Fox, an associate professor of criminology at the University of South Florida in Tampa. Gabby Petito and Brian Laundrie. via Instagram Laundrie, 23, of North Port, Florida, may have had financial or transportation assistance eluding authorities, Fox said, adding that if someone picked him up hitchhiking or if he boarded a bus, witnesses probably would have gone to police or the media. "The idea that nothing has been said reinforces to me that he was likely getting help," Fox said. "Obviously, that person would have to be very loyal and very close to him ... to not compromise his identity." Laundrie's family said he went hiking Sept. 13 in the Carlton Reserve, which has been searched multiple times. Law enforcement officers were back at the 25,000-acre wildlife refuge Thursday, with his father, Chris Laundrie, helping, family attorney Steven Bertolino said. Again, the search came up empty, Bertolino said in a text message to Telemundo affiliate WRMD of Tampa. "Chris Laundrie accompanied members of law enforcement into the Reserve to show them the trails and places Chris and Brian have hiked and which Brian was known to frequent," Bertolino said. "There were no discoveries but the effort was helpful to all. It seems the water in the Reserve is receding and certain areas are more accessible to search. ... Hopefully Brian will be located soon." The unforgiving terrain and the weather could easily erase any evidence of Laundrie's presence, Fox said. "These factors that are here in Florida, a subtropical environment, are known to degrade evidence," she said. "Imagine a massive . . . read the full article here.