Tice, previously a U.S. Marine Corps officer who served in Iraq and Afghanistan, was reporting as a freelance journalist from inside Syria during the country's civil war when he stopped tweeting in August 2012.

A man identifying himself as Missourian Travis Timmerman tells CBS News he was liberated from a Syrian prison upon dictator Bashar al-Assad's ouster.

His parents say their son traveled to Hungary to write a book on old churches, but they have no idea how he ended up in Syria. They lost contact with him in May.