SARASOTA COUNTY (WFLA) – The search for Brian Laundrie is nearing the one-month mark. Law enforcement from across the region continues assisting the FBI in their ongoing search at the Carlton Reserve. K-9 units from Pasco and Brevard County Sheriff’s Offices were seen entering the reserve Thursday morning.

At this point, no suspects have been named in the death of 22-year-old Gabby Petito. The FBI is only calling Laundrie a person of interest in the case.

The 23-year-old was last seen by his parents more than one month ago. They claim he left their home to go to the Carlton Reserve for a hike.

Federal authorities haven’t divulged much information in their quest to bring the case surrounding Petito’s death to a close. 8 On Your Side spoke with a forensics expert who thinks, based on the information that’s been made public, this will be a difficult case to solve.

“Normally, we rely on a witness, we rely on statements, we rely on physical evidence,” said Peter Massey. “In this case, we probably don’t have a witness, unless Brian could be located and give us a statement, we don’t have any kind of statements or admissions and physical evidence, in this case, is very very limited. From the prosecution standpoint, it is going to be very difficult,” he continued.

Though Laundrie remains a person of interest in his fiancée’s death investigation, he is wanted by federal authorities for the unauthorized use of her debit card in the days following her demise.

“One of the reasons I think that they issued this warrant is that if they find Brian, they now have a legal reason to bring him in and at least offer up an opportunity for him to explain his side of the story,” explained Massey.