After a successful career in mathematics and computer science, receiving grants from the National Science Foundation and NASA, and being listed in Who's Who in Computer Science and Two Thousand Notable Americans, James R. Callan turned to his first love-writing. He has had four non-fiction books published. He now concentrates on his favorite genre, mystery/suspense/thriller. His fourteenth book releases in February, 2021. In addition, he speaks at conferences and gives workshops on various writing topics such as character development, dialog, audiobooks, plotting, and the mystery/suspense/thriller genre.

He and his wife split their time between homes in northeast Texas and Puerto Vallarta, Mexico. They have four grown children and six grandchildren.