Mark was hired by the Dallas Police Department in October1979. He was assigned to patrol, recruiting, crime analysis, financial crimes, homeland security, planning and the Caruth Police Institute CPI. He retired from DPD as a lieutenant in January 2017 and was assigned for his last four years as the department liaison with the Caruth Police Institute. He taught leadership and worked on basic research issues.
Mark co-authored two books on Microsoft Office. He has consulted throughout the US, Argentina, Trinidad and Tabogo and Romania. He earned a master’s degree in Management and Administrative Science, master and a Ph.D. degree in Public Affairs from the University of Texas at Dallas. Currently Mark works as a lecturer for the University of North Texas at Dallas.