After being identified as a person of interest by police, the fiancé of the missing 22-year-old Gabby Petito is expected to be detained shortly in connection with her disappearance, according to a criminal defense lawyer.

After returning home to North Port, Florida, earlier this month without Petito and refusing to speak to authorities, Lara Yeretsian, a Los Angeles-based criminal defense attorney, told Fox News that she believes it is just a matter of time until police question Brian Laundrie.

Lawyer believes Brian Laundrie will soon be detained

Petito and Laundrie had taken a cross-country vacation in their van in June, visiting numerous states. Police in Moab, Utah, revealed bodycam footage of the couple from August 12 while responding to an argument between them earlier this week.

Petito's family reported her missing on September 11, ten days after Laundrie returned to the couple's house in North Port. The missing New York woman's family has already voiced their displeasure with Laundrie's refusal to cooperate with authorities to investigate her disappearance. Per Newsweek via MSN, protesters have also gathered outside Laundrie's parents' home, demanding answers to the 22-year-old's disappearance.

Sister of Gabby Petito's boyfriend speaks out

Cassie Laundrie, sister of Brian Laundrie, has come out regarding Petito's disappearance. Brian's sister claimed in a recent interview that the missing woman is "like a sister" to her and that she believes the situation is just "a big misunderstanding."

Gabby Petito, a New Yorker, has been missing since August 24, when she left a hotel in Salt Lake City, Utah, with her boyfriend, Brian Laundrie. Before her disappearance, she created a social media blog while traveling throughout the United States with her fiancé.

On Thursday, his sister Cassie appeared on ABC's Good Morning America for an interview. "Obviously, I and my family want Gabby to be found safe," she stated in a short clip that aired before the full Friday episode.

It comes after the missing woman's family pleaded with her partner's parents for assistance, saying their "lives are falling apart." The family claimed they have been unable to sleep or eat as they continue to seek their "beautiful" daughter in a heartfelt message shared on social media, MIRROR reported.

The missing woman's family asked Brian Laundrie to provide additional information about her disappearance in a letter sent to his parents and shared on social media. Authorities have sought to contact him and his parents, but they have so far refused. On Tuesday, Laundrie sent a statement through his legal team, breaking his silence for the first time.

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Utah police look into the link between Petito's disappearance and a double-murder case

Meanwhile, authorities in Utah are looking into a possible link between the disappearance of "van-life" lady Gabby Petito and the death of a woman who worked at the Moab co-op where Petito and her fiancé Brian Laundrie had a heated argument.

Kylen Schulte, 24, and her wife, Crystal Turner, 38, were discovered dead and half-naked where they had been camped six days after Petito and Laundrie had a violent confrontation at Moonflower Community Cooperative.

Schulte and Turner informed acquaintances about a "scary man" who had been following them and that they would be murdered if something happened to them. Their corpses were discovered on August 18 at a campground in the La Sal Mountains, about an hour from Moab, as per Daily Mail.

Around the same time that Schulte and Turner were slain in Utah, authorities in San Miguel County, Colorado, issued a warning to campers after discovering more than 30 firearms at a man's campground in Telluride, a little over two hours from Moab.

His movements were unknown to authorities, and it is uncertain if he was finally apprehended. Police in Moab and North Port, Florida, where Petito and Laundrie lived, are now investigating possible connections between the double homicide and Petito's disappearance.

Knives, hatchets, a crossbow, and numerous swords were among the weapons discovered in Telluride. Police withheld the man's identity due to pre-trial publicity, and his whereabouts remained unknown as of August 23. On August 12, Petito and Laundrie got into a violent altercation inside the Moonflower co-op, a day before Schulte and Turner were last seen leaving a Moab pub.

Petito is shown on police bodycam film explaining why she smacked her boyfriend Brian Laundrie in a violent incident 13 days before she was last seen in Wyoming's Gran Teton National Park. She was on a cross-country vacation with Laundrie that was supposed to finish around Halloween, but her mother reported her missing two weeks after they last spoke on the phone.

Petito, 22, is seen on camera crying and telling authorities that she "was trying to get him to stop asking me to calm down" and that the pair had been arguing all morning.

Petito claims she has OCD and anxiety in the video, which was taken in Moab, Utah, and both she and Laundrie said she was anxious because of the YouTube blog they were working on to capture the doomed cross-country trip. Laundrie has scratches on his face and arm, which he claims were caused when Petito was attempting to steal the keys from him and struck him with her phone, according to an officer.

Related Article: Missing Woman Gabby Petito's Boyfriend Addresses Why He Won't Speak To Authorities; Police Name Him as "Person of Interest"