Family kept Mueller’s capture a secret

Messages were left on a U.S. flag in honor of Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott. The 26-year-old aid worker from Prescott was held by the Islamic State (ISIS), which claimed she was killed by Jordanian airstrikes in Syria. (Photo: Rob Schumacher/The Republic)

Mourners hold candles during a vigil for Kayla Mueller in Prescott Wednesday Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

Former Secretary of the State Ken Bennett holds a candle during a vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family February 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

The Rev. Kathleen Day gives a eulogy during a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family February 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

Carl Mueller (middle) holds a candle up toward the sky during a candlelight vigil for his daughter, Kayla, in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family February 10 while a hostage of ISIS in Syria. To the right of Carl is his wife Marsha. (Photo: Michael Chow/The Republic)

Marsha Mueller has her candle lit during a vigil for her daughter, Kayla, in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

A candlelight memorial was held in honor of Kayla Mueller Wednesday, Feb. 18, 2015 in Prescott. The 26-year-old aid worker from Prescott was held by the Islamic State (ISIS), which claims she was killed by Jordanian airstrikes in Syria. (Photo: Rob Schumacher/The Republic)

A candlelight memorial in honor of Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott. The aid worker from Prescott was held by the Islamic State (ISIS), which claims she was killed by Jordanian airstrikes in Syria. (Photo: Rob Schumacher/The Republic)

Mourners hold candles during a vigil for Kayla Mueller in Prescott Wednesday, Feb.18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

Eric Mueller talks during a candlelight vigil for his sister, Kayla, in Prescott Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family February 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

Eric Mueller (center) looks towards the sky during a candlelight vigil for his sister, Kayla, in Prescott Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

A candlelight memorial was held in honor of Kayla Mueller Wednesday, Feb. 18, 2015 in Prescott. The aid worker from Prescott was held by the Islamic State (ISIS), which claims she was killed by Jordanian airstrikes in Syria. (Photo: Rob Schumacher/The Republic)

Carl and Marsha Mueller attend the candlelight memorial in honor of their daughter Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott,. (Photo: Rob Schumacher/The Republic)

A candlelight memorial was held in honor of Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott. (Photo: Rob Schumacher/The Republic)

Tonya Castillo (left) comforts her daughter Tiffany Reid during a candlelight vigil for Kayla Mueller in Prescott February 18, 2015. Reid and Mueller were friends. (Photo: Michael Chow/The Republic)

Tonya Castillo (left) comforts her daughter Tiffany Reid during a candlelight vigil for Kayla Mueller in Prescott Feb. 18, 2015. Reid and Mueller were friends. (Photo: Michael Chow/The Republic)

Mourners attend a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. (Photo: Michael Chow/The Republic)

Carl Mueller (middle) holds a candle up toward the sky during a candlelight vigil for his daughter, Kayla, in Prescott Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. To the right of Carl is his wife, Marsha. (Photo: Michael Chow/The Republic)

Carl Mueller (middle) holds a candle up towards the sky during a candlelight vigil for his daughter, Kayla, in Prescott Feb. 18, 2015. To the right of Carl is his wife, Marsha. (Photo: Michael Chow/The Republic)

Carl and Marsha Mueller (center, left) attend a candlelight memorial in honor of Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott. (Photo: Rob Schumacher/The Republic)

Marsha Mueller (center, left) and her son Eric Mueller (right) receive hugs upon arriving at the candlelight memorial in honor of her daughter Kayla Mueller on Wednesday, Feb. 18, 2015 in Prescott. The aid worker from Prescott was held by the Islamic State (ISIS), which claims she was killed by Jordanian airstrikes in Syria. (Photo: Rob Schumacher/The Republic)

Cindy Craig (left) and Candice Fabrie embrace before a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family Feb. 10 while a hostage of ISIS in Syria. They volunteered alongside Mueller. (Photo: Michael Chow/The Republic)

Tim Ryerson deposits canned foods while Stephanie Bur (left), Angelique Ung (center) and Jonathan Ung sign a memorial book before a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. (Photo: Michael Chow/The Republic)

Candice Fabrie (left) and Cindy Ksenzulak hang a memorial signing book before a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. (Photo: Michael Chow/The Republic)

Candice Fabrie (left) and Cindy Craig embrace before a candlelight vigil for Kayla Mueller in Prescott Wednesday, Feb. 18, 2015. The Arizona aid worker was confirmed dead by her family February 10 while a hostage of ISIS in Syria. They volunteered alongside Mueller. (Photo: Michael Chow/The Republic)

Several local churches and community organizers are holding a candlelight memorial for Kayla Mueller at the Prescott courthouse square Wednesday, Feb. 18, 2015