Just before 2:30 p.m., San Francisco lost one sheriff and gained another. Vicki Hennessy was sworn in during a brief ceremony outside the mayor's office.
"I trust her, I know her, I know she will be a great leader for our department," Lee said.
The changing of the guard comes as the mayor officially suspended Mirkarimi after he pleaded guilty to false imprisonment in connection with a domestic violence incident involving his wife and then refused to step down as sheriff when given an ultimatum by Lee.
Mirkarimi's attorney David Waggoner was served with the written notice of charges, including the complaint that "Sheriff Mirkarimi's actions undermine the integrity of the Office of Sheriff. He misused the power and status accompanying his public office... This misconduct is fundamentally incompatible with holding the Office of Sheriff."
Hennessy retired last year after more than three decades of law enforcement experience, including as chief deputy of the sheriff's department and head of the city's Department Of Emergency Management.
Hennessy knows she's taking the position in a time of turmoil.
"It's daunting, but I think I'm the right person for the job based on my experience," she said.
Even before her swearing in, Hennessy met with the city's top public safety officials during a briefing on prison re-alignment.
Fire Chief Joanne Hayes-White says Hennessy has a lot of credibility.
"I think she has great leadership skills, she's outgoing, she's inquisitive and will work with all the members of the sheriff's department," she said.
Right after the swearing in, the new interim sheriff headed to the department that she will now oversee, but the man she is replacing may not go quietly. Mirkarimi is entitled to a hearing before the city's ethics commission and the Board of Supervisors. In the meantime, he's suspended without pay, but with his medical benefits.
The organization representing the command staff at the sheriff's department praised Hennessy's appointment, calling her the right person at the right time.
Mirkarimi did not comment Wednesday.