WASHINGTON — President Barack Obama on Tuesday named veteran Secret Service agent Julia Pierson as the agency’s first female director, signaling his desire to change the culture at the male-dominated service, which has been marred by scandal.

Pierson, who most recently served as the agency’s chief of staff, will take over from Mark Sullivan, who announced his retirement last month. The agency faced intense criticism during Sullivan’s tenure for a prostitution scandal during preparations for Obama’s trip to Cartagena, Colombia, last year.