Melissa McCormick was recently promoted to sergeant, making her the first woman to attain that rank in the Randolph Police Department. The department currently has 54 officers and five recruits in the police academy. Of the 59, five are women. McCormick, a Randolph native, has been with the department for seven years, rising through the ranks from patrol officer to detective and now to sergeant. For the past five years, she was police prosecutor, a post in which her duties included investigating insurance fraud and sexual assaults, working on the RAD (rape aggression defense) self-defense program, and grant writing. As sergeant, she said, “I will be going back to patrol [in uniform] where I will be the street supervisor for the day shift.’’ McCormick was sworn into her new role on Feb. 13. “I did not want to get promoted for the recognition,” she said. “I wanted to get promoted to instill an atmosphere of professionalism, teamwork, and dedication throughout the police department and the community. . . . The recognition I have received I take as an honor; however, doing a great job in this position will be a greater honor.’’