The FBI on Monday searched the Florida home of Brian Laundrie, the man named a person of interest in the disappearance of his fiancée, Gabby Petito.
The law enforcement agency said it was "executing a court-authorized search warrant today at the Laundrie residence in North Port, FL relevant to the Gabrielle 'Gabby' Petito investigation," and later tweeted that it was concluded. No further details were released.
Before FBI agents descended on the home shortly before 9:50 a.m., a man came outside, got documents from a car and returned to the residence, an NBC Miami reporter on the scene said.
Authorities later led a couple, believed to be Laundrie's parents, outside the residence, according to the reporter, Cristian Benavides. They were in a police car for about 20 minutes while the house was searched.
The couple was led back into the home, where they remained well into the afternoon with about 15 FBI agents, Benavides reported. Additional FBI agents were stationed outside the house, which was blocked off with crime scene tape.
Also on Monday, a search warrant affidavit noted that Florida authorities discovered a hard drive inside the couple's van on Tuesday.
The affidavit referenced concerns for Petito's mental health.
"Based on the totality of the circumstances related to the subject's mental health, I believe there is probable cause to believe the subject is unable to care for herself due to her increased anxiety. Due to this behavior, our concerns for her welfare have reached an exigent level," the affidavit noted. "Her cellphone has been turned off for approximately 15 days and there have been no sightings of her since August 27th, 2021."
The affidavit also noted that Petito’s mom, Nicole Schmidt, received an “odd text” on Aug. 27 from Petito’s cell phone.
The text read, "Can you help Stan, I just keep getting his voicemails and missed calls," according to the affidavit, which noted that Stan is the name of Petito’s grandfather. Schmidt, however, told police she never called him Stan.
“The mother was concerned that something was wrong with her daughter,” according to the affidavit. “This was the last communication anyone had with the subject. Her cellphone was no longer operational, and she stopped posting anything on social media about their trip. Per her family, this was not normal behavior for the subject, and they became more worried about her."
Authorities 'exhausted all avenues' in search for Laundrie in nature reserve
Meanwhile, the North Port Police Department said it had stopped looking for Laundrie in a 25,000-acre wildlife refuge where it had been focusing its search, adding that it "currently has no plans to conduct a major search of the Carlton Reserve today." The department said investigators had “exhausted all avenues" in the county park near Sarasota.
Authorities did not say Monday whether they were searching elsewhere for Laundrie, 23.
An attorney for the Laundrie family, Steven Bertolino, confirmed Monday that Laundrie’s parents told authorities that Brian Laundrie went to that preserve Tuesday and that's the last day they saw him.
The parents said they went to the reserve Wednesday to look for him, saw his car with a note from police saying the vehicle needed to be removed, but left it overnight so their son could use it to drive it back, according to the attorney. When he did not return Thursday morning the parents went back and took the car, the lawyer said.
Laundrie last week was named a person of interest in connection with his fiancée's disappearance, but police emphasized Friday that he is not wanted for a crime. Police in North Port, where the couple lived, and the FBI also said that they do not know where Laundrie is.
Petito's family addressed his disappearance, saying through a family attorney: "All of Gabby's family want the world to know that Brian is not missing, he is hiding. Gabby is missing."
Remains believed to be those of Petito were found Sunday at a campground in Bridger-Teton National Forest, near Grand Teton National Park in Wyoming, according to Charles Jones, the supervisory agent in the FBI's Denver office.
The remains were "consistent" with Petito, 22, he said.
A forensic investigation will confirm the discovery at the Spread Creek Dispersed Camping Area, Jones said, adding that a cause of death had not been determined.
911 audio released
The Grand County Sheriff's Office in Utah on Monday released 911 audio from a witness who said he saw a man slap a female and then saw a white Ford Transit van bearing a Florida license plate drive away.
The 911 call led Moab police to stop Petito's van on Aug. 12.
The witness told the dispatcher that he’d like to report a “domestic dispute.”
“We drove by and the gentleman was slapping the girl,” the witness said. “... And then we stopped. They ran up and down the sidewalk, he proceeded to hit her, hopped in the car, and then drove off.”
Moab police said on the afternoon of Aug. 12 they responded to a "domestic problem" between Petito and Laundrie.
The alleged altercation happened as Petito and Laundrie were driving toward Arches National Park, according to a police report.
The report indicated officers on scene had viewed Petito as the aggressor.
An officer wrote that Petito had slapped Laundrie after an argument, at which point Laundrie allegedly attempted to lock her out of the van. She forced her way back in before Laundrie drove off, according to the report.
The two told the officer that "they are in love and engaged to be married and desperately didn't wish to see anyone charged with a crime," the report said.
The pair was told to separate for the night, with Petito maintaining possession of the van. No charges were filed.
Petito stopped communicating with her family in late August
Petito was last known to have been in Grand Teton National Park late last month, when she stopped communicating with her family, police have said.
"I don’t even know what to say. I’m at a total loss. My heart is shattered #justiceforgabby," Petito's brother posted on Instagram on Sunday.
"#GabbyPetito she touched the world," her father, Joseph, wrote on Facebook. A photo of his daughter accompanied the caption.
A statement from the family's lawyer, Richard B. Stafford, asked for space to "allow them to grieve."
"Your tireless work and determination helped bring Gabby home to her parents. The family and I will be forever grateful," Stafford said.
A statement from the Laundrie family's lawyer Sunday called Petito's apparent death "heartbreaking."
"The Laundrie family prays for Gabby and her family,” the statement said.
Petito and Laundrie began a cross-country tour of national parks in July, documenting their journey on YouTube and Instagram using the hashtag #VanLife. Laundrie returned home to North Port, south of Tampa, in the couple's van Sept. 1 — 10 days before Petito's family reported her missing, police have said.
Schmidt said she last heard from her daughter at the end of August. Petito's last text read: "No service in Yosemite." It is unclear whether Petito sent that text message.
This story originally appeared on NBCNews.com.