Who is Brian Laundrie's older sister, Cassie Luycx?

Cassie Luycx, 31, has laid low following the disappearance and death of Gabby Petito, who would have been her future sister-in-law, and during the manhunt for her younger brother, 23-year-old Brian Laundrie, who is now a fugitive wanted for alleged debit card fraud and a person of interest in Petito's death.

"Law enforcement agencies are well aware of these dates," Bertolino told Fox News on Friday. "Any prior communication by Cassie that does not reflect these dates is simply a difference of relating an answer to a question misinterpreted by Cassie or poorly posed by the inquirer."

Luycx is the only member of Laundrie's immediate family who has said anything publicly about Petito's disappearance, telling ABC News on Sept. 17 that the oddest thing about the situation is she hasn't "been able to talk to [Brian]."

"I wish I could talk to him," Luycx told the news outlet. "I know that it's all because the lawyers, advising them not to say anything."