You can find the latest on the investigation involving Gabby Petito and Brian Laundrie hereDownload the WFLA app for breaking news push alerts and sign up for breaking news email alerts.

NORTH PORT, Fla. (WFLA) — The attorney for Brian Laundrie’s family says the 23-year-old’s parents now believe he left home one day earlier than they had originally told police.

Attorney Steve Bertolino texted WFLA on Tuesday confirming that the Laundries now believe their son left home to go hiking on Monday, Sept. 13. They had previously told police he left home on Tuesday, Sept. 14 when they reported him missing.

“The Laundries were basing the date Brian left on their recollection of certain events,” Bertolino said. “Upon further communication with the FBI and confirmation of the Mustang being at the Laundrie residence on Wednesday, Sept. 15, we now believe the day Brian left to hike in the preserve was Monday, Sept. 13.”

Laundrie’s parents officially reported him missing on Friday, Sept. 17 – more than two weeks after police say he returned home to North Port alone from a cross-country trip he had been on with his fiancée Gabby Petito.

Petito was reported missing by her family on Sept. 11. From the beginning of that missing person investigation, Laundrie and his parents vowed to remain in the background. Petito’s family and law enforcement investigating the case had voiced their frustrations with the lack of cooperation and answers.

Laundrie was named a person of interest in Petito’s disappearance on Sept. 15, three days after Laundrie’s parents now say he left to go on a hike in the Carlton Reserve, and two days before he was reported missing.

Petito’s body was found in Wyoming on Sept. 19. A federal arrest warrant was issued for Laundrie on Sept. 23 following a federal grand jury indictment for use of unauthorized access devices after Petito’s death.

The FBI is still searching for Laundrie. His parents have not publicly spoken about his disappearance, or the investigation into Petito’s death. However, his sister Cassie has spoken to protesters outside her home, as well as ABC’s Good Morning America.

Earlier Tuesday, the Laundrie family’s attorney confirmed what Cassie Laundrie told protesters outside her home – that Brian Laundrie flew home to Florida on Aug. 17 from Salt Lake City. According to Bertolino, Laundrie returned to Salt Lake City to “rejoin Gabby” on Aug. 23.

“To my knowledge Brian and Gabby paid for the flights as they were sharing expenses,” he said. “Brian flew home to obtain some items and empty and close the storage unit to save money as they contemplated extending the road trip.”