Mueller is the last known remaining American hostage in Syria. On Friday, ISIS claimed she was killed.
Mueller was taken hostage in 2013, but it was just this past Friday we learned of her capture.
Her family, friends, and politicians who were trying to help kept her capture a secret for more than a year and a half.
Her family reached out to Ken Bennett, the former AZ Secretary of State first met Kayla's father in August of 2013.
"If my daughters was in that kind of situation, I don't know what I would do," said Ken Bennett, former Arizona Secretary of State.
Bennett was in Prescott guest hosting a radio show, when he finished Kayla's father was in the lobby.
"He tells me I am Carl Mueller, I have a daughter Kayla and she is 25-years-old, and she has been doing humanitarian work in the Middle East, and she was captured 3-4 days ago by terrorists and I don't know what to do," said Bennett.
Bennett was able to put Kayla's father in touch with Congressman Paul Gosar and Senator John McCain. For the past 18 months everyone involved kept Kayla's situation a secret.
"They thought keeping this confidential was in the best interest of Kayla... I could tell in his eyes, in his body language, and in his voice that he was being totally truthful and he was just terrified, he didn't know what to do," he said.
Bennett stayed in touch with Kayla's family over the past 18 months. He says they remain hopeful that Kayla is still alive, despite what ISIS claims.
"I can't imagine the desperation, and the hopeless of a father in this situation... they want this focused on people understanding what a wonderful daughter they have and that she was trying to make a difference," said Bennett.
So far there has been no proof that Kayla was killed as a result of a Jordanian airstrike like ISIS claims. Jordan has dismissed the claim and US officials are skeptical too.