As the manhunt for Brian Laundrie in a Florida wildlife reserve continues after three weeks, his sister is pleading for him to turn himself in and "get us out of this horrible mess."
Laundrie's sister, Cassie Laundrie, said she does not know where the fiance of 22-year-old Gabby Petito is.
"I'd turn him in," she told ABC News in an interview that aired Tuesday.
"I worry about him. I hope he's OK, and then I am angry and don't know what to think. I would tell my brother to just come forward and get us out of this horrible mess," she said.
Laundrie, 23, is wanted in connection with the disappearance and murder of his fiancee, Petito. Though he has not been charged with her murder, he is considered a person of interest. Laundrie has been charged with unauthorized use of a Capital One debit card and several accounts involving more than $1,000.
Petito's body was found on Sept. 19 at a campground near Wyoming's Grand Teton National Park. Her death was ruled a homicide.
Laundrie was last seen after he returned to Florida on Sept. 1 without Petito. The couple had set out on a cross-country trip in a shared van in mid-June. Officials say Laundrie refused to share information with investigators after Petito was reported missing by her family on Sept. 11.
His parents initially told authorities that Laundrie said he was going hiking in the nearby Carlton Reserve on Sept. 14. According to the Laundrie family's attorney Steven Bertolino, that date was inaccurate.
"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," he told Fox News Tuesday.
Cassie Laundrie said she has tried contacting Brian Laundrie since his disappearance, but phone calls went to voicemail. She said she personally last saw him on Sept. 6 during a family camping trip.
"There was nothing peculiar about it. There was no feeling of grand goodbye. There was no nothing," Cassie Laundrie said.
Authorities last week said they were scaling back the search for Brian Laundrie at the 24,000-acre reserve in Sarasota County and would rely on "targeted based on intelligence." Authorities have used a diver unit, dogs, drones and ATV vehicles to search the wetlands.
"I'd say Brian is a mediocre survivalist. It wouldn't surprise me if he could last out there a very long time," Cassie Laundrie said.
Bertolino has maintained that Brian Laundrie's family members have not "assisted" Laundrie in his evasion of police. Cassie Laundrie said she did not know whether her parents had helped her brother.
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On Tuesday, Bertolino also said Brian Laundrie had flown home on his own Aug. 17, during the cross-country trip, and then returned to Petito in Salt Lake City on Aug. 23, adding to the publicly known timeline of Brian Laundrie's disappearance, according to ABC News.
Cassie Laundrie said she did not see signs of any domestic violence between her brother and Petito. On Aug. 12, a witness to a dispute between the two of them called police in Moab, Utah, and police pulled over the couple's van. According to the witnesses' call, "the gentleman was slapping the girl."
Moab police's response has been heavily scrutinized, and the city said it has opened an investigation into their interaction with Brian Laundrie and Petito. Body camera footage showed Petito claiming she had hit Brian Laundrie first, before he also "grabbed" her face "with his nail." The couple reportedly separated for the night, but no charges were filed.
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The case has fueled national speculation about Brian Laundrie's whereabouts, his involvement with Petito's murder and his family's knowledge of the events. People have used social media to search for clues, and so far several reported sightings have not panned out.
"I hope my brother is alive because I want answers just as much as everybody else," Cassie Laundrie said.