(ABC4) – For the second time this week, the sister of Brian Laundrie has spoken out about the disappearance of her brother.

In early September, Brian Laundrie returned to his Florida home, alone, from a cross-country road trip with his girlfriend Gabby Petito. Within three weeks of his return, Laundrie had disappeared and Petito was found dead. Since Petito was found dead, a federal arrest warrant has been issued for Laundrie. A manhunt has been ongoing since mid-September.

On Monday, a video shared exclusively with ABC4 affiliate NewsNation showed protestors speaking with Laundrie’s sister, Cassie, outside her Florida home. During the video, which you can see here, Cassie clarifies some of the timeline around Brian’s disappearance and Petito’s death.

Cassie explains she saw Brian on two different occasions – on Sept. 1 when he and their parents arrived at her home and five days later during a family vacation to a Florida campground. She adds that she has not been able to speak with her family during the investigation.

“I’m in the boat where I’m getting ignored by my family and thrown under the bus by my family’s attorney,” she said. The Laundrie family’s attorney, Steven Bertolino, shared a statement with NewsNation, saying he does not represent Cassie.

WATCH: Cassie Laundrie speaks with protestors outside her home

On Tuesday, Cassie did an exclusive interview with ABC News. During the interview, which you can see here, Cassie says she does not know where Brian is and if she did, she’d “turn him in.”

“I really wish he had come to me first that day with the van because I don’t think we’d be here,” Cassie tells ABC News. “I worry about him, I hope he’s okay and then I’m angry, I don’t know what to think. I would tell my brother to just come forward and get us out of this horrible mess.”

She continues, saying she has not seen or spoken with Brian since the family camping trip in Fort De Soto. During that time, Cassie says “there was nothing peculiar about it.”

“I’m frustrated that, in hindsight, I didn’t pick up on anything. It was just a regular visit,” she tells ABC News. She also called the Moab Police body camera video of an incident between Petito and Brian “disturbing to watch.” She adds that if her parents are involved, they should “come clean.”

As the manhunt for Brian continues, Cassie says he has taken trips for five days at a time on the Appalachian Trail and calls him a “mediocre survivalist.” ABC News reports multiple possible sightings of Laundrie have been reported here, including a hiker who called 911 to say he believed he had spoken with Laundrie over the weekend.

“I hope my brother is alive because I want answers just as much as everyone else,” Cassie tells ABC News, adding that if she knew where he was, she’d “turn him in.” You can watch the full ABC News interview here.

For continuing coverage of the Gabby Petito case, including body camera video from the Moab incidentpostcards Petito sent to Laundrie’s sister, and more, click here.