The death of a young black woman in a stolen car proved to be the breaking point in a series of shootings and racially tinged scandals that led to the resignation of San Francisco’s police chief.

A new acting chief is now tasked with mending the department’s strained relations with the black community. Deputy Chief Toney Chaplin, a 26-year department veteran who is black, was appointed by the mayor after Greg Suhr stepped down Thursday, hours after the woman was shot.

Chaplin has the confidence of at least one key supporter.

“Toney Chaplin has the charisma, chemistry and courage to lead this department,” said the Rev. Amos Brown, president of the San Francisco chapter of the NAACP.

Brown also supported Suhr through the department’s difficulties and said the police’s problems “are bigger than one man.”

But pressure has been mounting for new leadership since December, when five officers fatally shot a young black man carrying a knife. Since then, there have been protests, moves to reform the police department and a federal review of its protocols.

Mayor Ed Lee supported the chief in December and again in April after revelations that three officers had exchanged racist text messages. But hours after Thursday’s shooting, Lee asked for Suhr’s resignation and received it.

“The progress we’ve made has been meaningful, but it hasn’t been fast enough,” Lee said in a brief statement at City Hall. “Not for me, not for Greg.”

Suhr could not be reached for comment Thursday.

The two had stood together through several scandals, announced a series of reforms aimed at reducing police shootings and called in the U.S. Department of Justice to review the force’s policies and procedures.

Suhr had been criticized for moving too slowly to fire several officers who exchanged racist text messages dating back to before his time as chief. All of them retained their jobs because Suhr failed to start disciplinary action when he first found out about the inappropriate conduct.

New disclosures later followed that other police also had sent racist texts.

Protesters demanding Suhr’s resignation drowned out the mayor’s second inaugural speech in January, and demonstrators forced Lee to abandon a planned speech on Martin Luther King Jr. Day later that month.

Suhr renewed his call for reform April 8 after an officer shot and killed a Latino homeless man who police said refused orders to drop a large knife.

But he lost the mayor’s backing Thursday, after a patrol car searching an industrial neighborhood for stolen vehicles came across a 27-year-old black woman sitting behind the wheel of a parked car.