With her brotherBrian Laundriestill missing, his sister Cassie Laundrie has spoken out once again, asking that her fugitive brother turn himself in immediately.

“I really wish he had come to me first that day with the van, because I don’t think we’d be here,” Cassie said during the interview, which aired onGMATuesday morning.

On Sept. 1, after traveling across the country with her in a converted van, Laundrie returned to his parents' home without Petito, 22. The couple had been out on the road together for about two months.

Gabby Petito and Brian Laundrie

On Sept. 19, Petito was found dead in Grand Teton National Park in Wyoming, and officials have since determined thather death was a homicide.

Petito, a native of Long Island, N.Y. was last seen alive in late August.

Cassie Laundrie is the only member of the family who has spoken to the media.

Last month,she spoke toGMA, and said she and her family wanted Petito to “be found safe.”

Added Cassie: “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.”

In Tuesday’s interview, Cassie said she hopes her brother is alive, but says she has no idea where he could be.

She said if she did know his location, she would “turn him in.”

Cassie last saw Brian on Sept. 6, when their entire family visited Fort De Soto Park in Florida’s Pinellas County.

Gabby Petito, Brian Laundrie

“I’m frustrated that, in hindsight, I didn’t pick up on anything,” Cassie added. “It was just a regular visit.”

Additionally, Cassie said, “I’m angry and I don’t know what to think.”

She added, “I hope my brother is alive because I want answers just as much as everybody else.”

Investigators have yet to say how Petito was killed, but believe she died sometime between Aug. 27 and Aug. 30.

Gabby Petito’s Father Joe Petito Says His Late Daughter ‘Is Already Saving Lives’ of Others

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A warrant for Laundrie’s arrest was issued in late September on the unauthorized use of a debit card charge. In addition, he has been named a person of interest in Petito’s case — but has not been named a suspect in connection with her death.

Police believe that the relationship between Petito and Laundriebecame more strained during their tragic road trip, according to a recently unsealed search warrant connected to the case.

Petito’s best friend, Rose Davis,told PEOPLEthe couple’s relationship was “toxic,” and that Laundrie had “jealousy issues.”

If you have information on this case, call 1-­800-­CALL-­FBI (225­-5324).

source: people.com