BALTIMORE (AP) — The beleaguered Baltimore police force has been reeling from scandal to scandal as it tries to cope with a soaring violent crime rate. The latest: Police Commissioner Darryl De Sousa's resignation , after only 116 days on the job, while facing charges of not filing his taxes.

Here is a look at the controversies and struggles the department has faced in recent years:

REVOLVING COMMISSIONERS

De Sousa, who took over leadership of the police department earlier this year, was the third person to hold the post over the last three years and the ninth since 2000.

In firing the previous commissioner, Mayor Catherine Pugh said a change in leadership was needed immediately to address violence more quickly. De Sousa was touted as a change agent, and he promised to stamp out police corruption and make other big changes.

Although violent crime rates in Baltimore have been high for decades, the churn in leadership comes as the city deals with what has been its highest-ever annual homicide rate: roughly 56 killings per 100,000 people last year. By comparison, the much-larger New York City had fewer than four killings per 100,000.

FREDDIE GRAY

In 2015, the death of Freddie Gray from a spinal injury the black man suffered inside a police van sparked massive protests and the city's worst rioting in 40 years.

Tensions were still smoldering when the city's top prosecutor charged six officers involved in Gray's case.

But three of the officers were acquitted, Marilyn Mosby dropped the remaining cases, and the Justice Department declined to charge the officers with civil rights violations, so no one was held criminally responsible.

CONSENT DECREE

Baltimore recently concluded its first year under a federal oversight program requiring sweeping police reforms. The process still has years to go.

The consent decree was authorized in January 2017 after a scathing Justice Department report detailing longstanding patterns of racial profiling and unconstitutional policing. And at a recent public court hearing to review initial progress, a federal judge didn't mince words.

U.S. District Judge James Bredar described the relationship between the police department and the community it serves as "fundamentally broken." He said the force has displayed a "lack of integrity" for years, and only "a lot of sweat" would solve "deep and embedded" problems.

GUN TRACE TASK FORCE

The legacy of a corrupt unit of detectives charged with racketeering continues to unfold.

The elite Gun Trace Task Force unit was tasked with getting illegal guns off the streets of Baltimore, but federal prosecutors say members used their position to detain people on false pretenses, steal their money, fake police reports, lie to investigators and defraud their department.

Public defenders are calling into question every case touched by the officers, several thousand of them over the last decade. More than 100 tainted cases have already been dropped.

Rumors have also swirled about the unit in connection with unsolved killing of Det. Sean Suiter, who was shot on duty with his own gun a day before he was to testify about the indicted officers before a federal grand jury. The unsolved case remains a homicide investigation led by Suiter's fellow detectives, though an independent panel is also reviewing it.

In December, the FBI declined to accept then-Police Commissioner Kevin Davis' request for federal agents to lead the Suiter investigation. De Sousa later formed the independent board.

Authorities have repeatedly said there's no evidence connecting Suiter's death to his scheduled testimony.