Gabby Petito Update: Brian Laundrie's Sister Speaks Out

Cassie Laundrie, the sister of Gabby Petito's fiance Brian Laundrie, spoke out about Petito's disappearance Friday, while Laundrie has refused to speak with authorities. Petito, 22, has not been heard from since Aug. 25, and her mother reported her missing on Sept. 11. Laundrie, 23, was formally named a person of interest in the case this week. In an interview with Good Morning America, Cassie said Petito is "like a sister" to her.

"Obviously, me and my family want Gabby to be found safe," Cassie told GMA. "My children love her, and all I want is for her to come home safe and found, and this to be just a big misunderstanding." Cassie has been cooperative with authorities, and said she hopes Petito is still alive. "I talked to the police the second they called," she said. "I called them right back. We were in Orlando on vacation with my kids at Disney and we came back to this." She has not spoken to Brian himself since Sept. 1.

On the same day Cassie's interview aired, Florida police were seen at the Laundrie home, reports ABC News. They did not speak with Laundrie himself, but with other members of the family "at their request." The North Port, Florida police department hoped Laundrie and his parents were open to speaking with them. He has no prior criminal history and there are no documented cases of domestic issues between him and Petito, police said.

In early July, Petito and Laundrie started a trip across the U.S. in a white Ford Transit van, leaving Florida and plans to go to New York, where Petito is from. Petito documented the trip on YouTube. She was last heard from on Aug. 25, when the two stopped at Grand Teton National Park on their way to Yellowstone. Six days later, Laundrie suddenly arrived at his parents' home in North Port. Petito's mother filed a missing persons report on Sept. 11. "The only reason you invoke your Fifth [Amendment right], in my opinion, is because you don't want to incriminate yourself," Petito's father, Joseph Petito, told PEOPLE. "I'm not trying to accuse nobody, but right now, it looks like you are guilty."

This week, police named Laundrie a person of interest, as he has not spoken to them. Moab, Utah authorities also released body camera footage from Aug. 12, when Petito and Laundrie were pulled over because they received 911 calls about a domestic disturbance. In the footage, a crying Petito told police the two were fighting over "personal issues." Utah investigators looked into a possible connection between Petito's disappearance and the brutal murders of Kylen Schulte and Crystal Turner, but found no connection, reports KUTV. Schulte worked at Moonflower Co-Up, the store where Petito and Laundrie were seen fighting near.

No charges were filed in the Utah incident. Cassie told GMA the two often got into arguments. "It looks typical of both of them," Cassie said. "Whenever they fight, they would take a little break and come back and be fine."

Petito is described as white, 5 feet, 5 inches tall, and 110 lbs. She has blonde hair and blue eyes, and several tattoos. Anyone with information about Petito's whereabouts are asked to call 800-CALL-FBI.