Law enforcement officials searched a vast Florida preserve Saturday for Brian Laundrie, the fiance of a 22-year-old woman reported missing after he returned from a cross-country trip without her and refused to speak with authorities.

The North Port Police Department announced on Twitter that it was working with the FBI and agency partners to search the Carlton Reserve, a nearly 25,000-acre prairie and wetlands area located in Sarasota County, in the southwest part of the state.

“His family says they believe he entered the area earlier this week,” the department stated Saturday, later saying it had suspended the search for the night.

Laundrie and Gabrielle “Gabby” Petito had been living out of a van and traveling to national parks in recent months, sharing posts on Instagram from scenic locations. But there had been at least one troubling incident during the journey. Body-camera footage released by police in Moab, Utah, shows the pair got into an emotional fight before she disappeared.

Her family has implored Laundrie and his relatives to share any information on her whereabouts. He has not been charged but is also not cooperating with the investigation. Laundrie’s relatives told investigators they have not seen him since Tuesday, police said.

On Friday, North Port police said they are conducting missing-person investigations and not a criminal investigation.

“We understand the community’s frustration, we are frustrated too. For six days, the North Port Police Department and the FBI have been pleading with the family to contact investigators regarding Brian’s fiancee Gabby Petito,” the North Port police said. “Friday is the first time they have spoken to investigators in detail.”

Richard B. Stafford, an attorney for the Petito family, said in a statement late Friday: “All of Gabby’s family want the world to know that Brian is not missing, he is hiding. Gabby is missing.”

Neither Stafford nor Steven Bertolino, the Laundrie family’s attorney, immediately responded to requests for comment early Saturday. Josh Taylor, a North Port police spokesman, told CNN late Friday that the search for Laundrie was “another twist in the story.”

Friday’s announcement from police comes weeks into a case that has garnered nationwide headlines as authorities have contended that the investigation was hindered by Laundrie and his family not coming forward with information about Petito’s disappearance. Bertolino has said he asked Laundrie and the family not to speak with investigators.

Protesters have camped outside the Laundries’ home for the past couple of days as Petito’s family has urged his family to assist in the investigation.

Cassie Laundrie, Brian’s sister, said in a Friday interview with ABC’s “Good Morning America” that she has not spoken to her brother since he returned to Florida. She is the first member of the Laundrie family to speak publicly about the case.

“Obviously, me and my family want Gabby to be found safe,” she told ABC. “She’s like a sister and my children love her, and all I want is for her to come home safe … and this to be just a big misunderstanding.”

The engaged couple started their cross-country journey in July from Long Island, where the childhood sweethearts both grew up, and they indicated on social media that they intended to reach Oregon by Halloween. Gabby Petito documented the trip on YouTube last month in a video titled, “Beginning Our Van Life Journey.”

Petito disappeared shortly after she contacted her family in late August from Grand Teton National Park in Wyoming, authorities said. Brian Laundrie returned home Sept. 1, and Petito’s family recently filed a missing-person report with police in Suffolk County, N.Y.

The case took a turn this week when body-camera footage was released by police in Utah. The video shows Petito and Laundrie being pulled over on Aug. 12 after their van was seen speeding and hitting a curb near the entrance to Arches National Park.

A witness called 911 on Aug. 12 after he saw Petito and Laundrie squabbling over a phone outside the Moonflower Community Cooperative, a natural food store in Moab, according to a police report obtained by The Washington Post. The onlooker said he saw Petito slap Laundrie during an argument before climbing into the vehicle through the driver-side window “as if Brian had locked her out and she was trying to find a way in,” the police report said.

When a Moab officer turned on his cruiser’s lights to stop the white 2012 Ford Transit van, Petito grabbed Laundrie’s arm to get his attention and caused the vehicle to swerve into the curb before it stopped, according to a police report. Police documented that Petito was “crying uncontrollably” and that she could not “stop crying, breathing heavily, or compose a sentence without needing to wipe away tears, wipe her nose, or rub her knees with her hands.”

She told police that the couple had been fighting all that morning over “some personal issues,” according to the video, and Petito noted that she had obsessive-compulsive disorder.

“Some days, I have really bad OCD, and I was just cleaning and straightening up and I was apologizing to him, saying that I’m so mean because sometimes I have OCD and get frustrated,” she said on the side of a Utah highway near the national park.

Petito told authorities that Laundrie initially wouldn’t let her in the car.

“Why wouldn’t he let you in the car?” the officer asked.

“He told me I needed to calm down,” she said, fighting back tears. “But I am perfectly calm.” She added, “He really stresses me out.”

Laundrie acknowledged that the couple had gotten into a minor scuffle after he climbed into their converted sleeper van with dirty feet, body-cam footage shows. He told police that weeks of traveling with each other had placed an “emotional strain” on their relationship and that the arguments between the two had increased since the start of the trip. He said the scratches on his face and arm occurred after the altercation at the Moonflower co-op.

The officer concluded in his report that he did “not believe the situation escalated to the level of a domestic assault as much as that of a mental health crisis,” and authorities did not file any charges. Police decided to separate the couple for the night, with Laundrie checking in to a motel and Petito staying in the van.

Officers decided Petito was the aggressor in the incident, but Laundrie did not want to bring a domestic violence charge against her.

“I’m not going to pursue anything, because she is my fiancee, and I love her,” Laundrie said, according to the video. “It was just a squabble. Sorry it had to get so public.”

Toward the end of the body-cam footage, an officer is heard passing along messages between Petito and Laundrie about how they were eager to reunite after they had time to decompress.

“Everything’s going to be okay,” the officer told her, according to video.

Katie Shepherd contributed to this report.

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