On Wednesday, law enforcement combed the Carlton Reserve, a nearly 25,000-acre preserve in Sarasota County, Florida.
Steven Bertolino, the attorney for the Laundrie family, said Chris Laundrie was asked to assist law enforcement in their search for Brian at the preserve. Since the preserve has been closed to the public, Chris has not been able to look for Brian in the only place Chris and Roberta believe Brian may be.
"Unfortunately North Port police had to postpone Chris' involvement but Chris and Roberta are hopeful there will be another opportunity to assist," Bertolino said.
It comes as the attorney for Brian Laundrie's family has confirmed that Brian flew home to Florida and then back to Utah, in the middle of the couple's road trip.
The attorney says Brian went to Florida to obtain some items and close a storage unit, leaving his fiancee alone out west.
Laundrie returned to Utah on August 23, four days before Petito was last seen alive. Petito, 22, was found dead in Wyoming on September 19.
Laundrie's trip back to the Tampa area came five days after he and Petito were stopped by police in Moab, Utah, when witnesses reported the couple was engaged in a domestic violence incident in Moab.
Laundrie is still missing.
The attorney for his family says that his parents last saw him on September 13 and not the following day, as they originally told police.
They say he went to go on a hike at the nearby Carlton Reserve.
The clarification came after further communication with the FBI.
"The Laundries were basing the date Brian left on their recollection of certain events. Upon further communication with the FBI and confirmation of the Mustang being at the Laundrie residence on Wednesday, September 15, we now believe the day Brian left to hike in the preserve was Monday September 13," Bertolino said.
His sister, Cassie, spoke out exclusively to ABC News about her brother's disappearance.
Cassie Laundrie says she last saw her brother at a Florida campsite with her family days before he was reported missing.
She said she had no idea anything was amiss and didn't realize at the time that he had returned home from his road trip without Petito.
"I really wish he had come to me first that day with the van, because I don't think we'd be here," she said. "I worry about him. I hope he's OK, and then I'm angry and I don't know what to think."
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