Mark is a former Marine who's worked in law enforcement over twenty-eight-years. In his career, Mark has served as a patrol officer, an undercover narcotics agent, a S.W.A.T. Team member, and a homicide detective.

Mark has parlayed his police experiences into a successful speaking and writing career. He has written articles for Focus on the Family's Breakaway magazine, Lookout magazine, and Christian Fictiononline and is also the author of five novels: Rolling Thunder, From the Belly of the Dragon, The Void, The Corruptible, and the Christy nominated The Night Watchman. Mark has also co-written two books with Max Lucado—Pocket Prayers for Dads and Pocket Prayers for Military Life.

He and his family currently live in central Florida.