Laundrie's sister says she saw no violence between him and Gabby Petito

New video of Gabby Petito reveals what she said to police 2:20

(CNN) -

Cassie Laundrie says she never saw any signs of domestic violence between her brother, Brian, and Gabby Petito.

He also reaffirmed that he does not know where his brother is.

Referring to the Aug. 12 meeting with police officers in Moab, Utah, in which Gabby Petito and Brian Laundrie describe an altercation between the couple to officers, Cassie told ABC's "Good Morning America" ​​that it was " painful "to see it, issued this Tuesday.

• New video reveals what Gabby Petito told police about Brian Laundrie

Several videos taken by body cameras of officers who responded to a 911 call detail the exchange between police and Petito, including Petito telling officers that although Laundrie had hit her, she hit him first, CNN previously reported.

Cassie Laundrie, sister of Brian Laundrie.

(Credit: ABC's "Good Morning America")

"It's definitely painful to see everyone upset. It was quite typical for them to argue and try to distance each other, but people who say they saw domestic violence in public, I've never seen anything like that from any of them," he said. .

"I do not know where it is"

"No, I don't know where Brian is. I would deliver him," Laundrie said in the exclusive interview aired Tuesday.

Cassie said if she could talk to Laundrie, she would tell her to introduce herself.

"I worry about him. I hope he's okay, and then I get mad and I don't know what to think. I'd tell my brother to come forward and get us out of this horrible mess," he said.

Cassie said the last time she saw Laundrie was during the family camping trip at Fort De Soto Park in Florida, which the family did in early September.

They honor the memory of Gabby Petito 0:49

The Laundrie family stayed at the campground, about 75 miles from their home in North Port, FL, from Sept. 6-8, the same period that Brian Laundrie returned to Florida without his fiancée Gabrielle Petito, CNN previously reported.

Cassie Laundrie told "Good Morning America" ​​that the last time she saw and spoke to him was on September 6.

"We only stayed for a couple of hours, had dinner and had marshmallows around the campfire and left. There was nothing peculiar about it. There was no feeling of great parting. There was nothing," Cassie said of her last encounter with Laundrie, adding after that she was "frustrated" for not having caught anything.

"It was a normal visit," he said.

Gabby petito