(NewsNation Now) — After no action at the Carlton Reserve for days, car after car of law enforcement, including a K-9 forensics unit, arrived Thursday to resume the manhunt for Brian Laundrie.

The Pasco County, Florida Sheriff’s Office confirmed they were called in by the FBI, and are using their human remains detection K-9 at the reserve.

The 24,000-acre reserve is a difficult place to search. Crews have been through it several times in the past month. However, the area is now dryer than it has been previously.

Investigators refused to comment on whether they believe they’re more likely to find Laundrie’s body than finding him alive. Last Friday, North Port police told NewsNation they believed there was a 50/50 chance Laundrie was still alive.

Without bringing Laundrie in for questioning, it’s possible we may never know exactly how or why Gabby Petito died.

“I don’t think that if we were to locate his body in the preserve that it is going to benefit one way or the other the investigation,” said Peter Massey, a forensics expert. “It will provide closure to the Laundrie family. I don’t think it is going to provide closure for the Petito family. They want to know how, why, when — all those important things.”

Laundrie has not been charged in her death, but has been ruled a person of interest and may have been among the last to see her alive. Petito last spoke with her family Aug. 25. Brian Laundrie returned from their cross-country road trip alone Sept. 1.

Laundrie was indicted on a bank fraud charge last month stemming from the use of Petito’s debit card. Prosecutors say he accessed her account some time around the end of August.

Palm Beach County, Florida State Attorney Dave Aronberg told NewsNation one complication with charging Laundrie with anything more while he’s a fugitive is they carry time limits that could expire if Laundrie is not found.

Some have speculated that Laundrie’s parents or his lawyer, Steven Bertolino, may know where he is. However, when NewsNation’s Brian Entin asked Bertolino if he knew, he replied, “No, I do not.”