In the late 1990s, she began her career at the American Prosecutors Research Institute as Senior Attorney. Over the following years, Harp served as a teacher at the National Advocacy Center in Columbia, S.C., program manager for the Home Improvement Fraud Against Seniors Program, senior attorney for the Sexual Assault and Violence Against Women Unit, project director for the Performance Measures for the Juvenile Justice System, and director of the National Juvenile Justice Prosecution Center.