On Sunday, more than 50 law enforcement officers began a second day’s search in a large wildlife area near Florida’s Gulf Coast to find a 23-year old man authorities consider a person-of-interest in the disappearance and disappearance of his girlfriend. The woman disappeared while on a cross country trek.

Brian Laundrie was found on the more than 24,000-acre (9.712-ha) Carlton Reserve in Sarasota County. This wildlife area has more than 100 miles (160 km) of trails and campgrounds.

Gabrielle “Gabby”, 22-year-old Laundrie, left July to embark on a cross country trek in a van that was converted for use in visiting national parks in the U.S. West. According to police, Laundrie was driving the van home to North Port, Florida on September 1. Petito’s family filed an missing persons report with the police in Suffolk County, New York on Sept. 11.

Laundrie was identified as a person in interest in the case.

North Port police released a statement saying that Brian was a person of concern in Gabby’s disappearance but not wanted for any crime. The police stated that the case is now a multi-missing person investigation.

Investigators were told by Laundrie’s relatives that they last saw him Tuesday. They believe he was at the Sarasota wildlife reserve.

Petito’s family was begging the Laundrie family for information about where their son had last seen her. Petito and Laundrie met as childhood sweethearts while growing up in Long Island, New York. His parents moved to North Port, approximately 35 miles (55 km) south of Sarasota.

The couple began their trek in the Fort Transit van in July from Long Island. According to their social media accounts they intended to reach Oregon by October’s end. However, Petito disappeared in late August after she last saw family at Grand Teton National Park, Wyoming. Authorities said that Petito was not found.

According to the FBI, Denver, agents began conducting ground surveys in Grand Teton National Park with assistance from the National Park Service, and are looking for clues regarding Petito’s disappearance.

FBI agents stated that they were looking at an undeveloped camping area close to Spread Creek, on the east border of the park. This area was closed to the public during surveys. They asked anyone who was there between Aug. 27-30 to contact them if they had seen Petito, Laundrie, or their vehicle.