Mark started his career in 1987 in Army Special Operations with the 3rd Battalion, 75th Ranger Regiment. He also worked at 4th Ranger Training Battalion, and was one of the first Instructors at the National Guard Bureau Scout Sniper School at Camp Robinson in North Little Rock, Arkansas. In 1998, Mark joined the US Border Patrol and was assigned to the Ysleta Border Patrol Station until just after 9/11. Immediately after 9/11, Mark was one of the original Federal Air Marshals who stood up the Orlando Field Office. In 2007, Mark accepted a job with the Defense Intelligence Agency as an Intelligence Officer and conducted clandestine intelligence operations across four deployments in Iraq and Afghanistan among other countries.

In 2015, Mark left government service for the private sector where he continued to work as an independent contractor in the Middle East and Africa, as well two more deployments to Iraq in 2016. In 2017, Mark was the original Project Manager responsible for standing up the WPS2 TO-12 contract security element for the US State Dept. Mission in Mogadishu, Somalia. Mark also competes locally in USPSA matches.