OAKLAND -- Howard Jordan stunned city leaders and many of his own officers Wednesday by stepping down as police chief, ending a tumultuous 19-month tenure marked by a staggering rise in crime and the department losing much of its autonomy to a federal overseer.

Jordan, 47, cited an undisclosed medical condition for his sudden departure and said he would seek a medical retirement in an email sent to staffers. Anthony Toribio, 46, a 23-year department veteran, will serve as interim chief, while the city begins a national search for a new chief.

"I take Howard at his word," said Mayor Jean Quan, who has known him for 20 years. "I think he loved his job. I think he loved this city."

Jordan's sudden departure came one week after the department's federal overseer, Thomas Frazier, issued a report critical of department leadership for not holding accountable rogue officers and commanders when they violate department rules. Frazier, a former Baltimore Police Commissioner who had the power to seek Jordan's ouster, also wrote that he plans to reopen several internal affairs cases in which officers were cleared of wrongdoing.

"The report was a condemnation of his leadership," said attorney John Burris, who represented plaintiffs in the decade-old Riders police brutality case that first put the department under federal monitoring.

"I think the chief took a pre-emptive approach and retired before he was asked to leave," Burris said.

Jordan, who has a wife and two daughters, told KGO-TV Channel 7 that he was "never forced out" and that he had been talking to his physician for "quite some time" about a "debilitating health condition."

"What I'm looking for is longevity, peace and harmony and to be able to watch my daughters graduate high school, from college ... get married -- all those fun things that people should do," he said.

City Administrator Deanna Santana refused multiple times during a Wednesday news conference to discuss whether Frazier had raised concerns about Jordan.

City leaders had initially scheduled a news conference Wednesday to unveil new crime-fighting initiatives but had to switch gears when they learned of Jordan's pending retirement. Councilman Larry Reid said Jordan didn't inform council members of his plans last night during a closed door council session.

Oakland's next chief will be its fifth since 2004. The job has long been considered one of the toughest in law enforcement given the city's crime problems, politics and the demands of a court-mandated reform effort to increase officer accountability and help the department better police itself in the wake of the Riders scandal.

The department's failure to satisfy the reforms, which were supposed to be completed in 2008, resulted last year in the city ceding unprecedented authority over the department to U.S. District Judge Thelton Henderson, who named Frazier to oversee the reform effort.

City leaders said they would work with Frazier on finding a new chief, which council members said could be a tough recruiting effort.

"We have a pretty difficult reputation to overcome in attracting great talent with the cloud of the federal court hanging over us," Councilwoman Libby Schaaf said.

Pete Dunbar, a former deputy chief in Oakland, said that Frazier might want to consider taking a stronger day-to-day role in the department given the relative youth of Toribio and the department's other commanders.

"It's not fair to (Toribio) to throw him in that fire," Dunbar said. "He needs people with experience and mentors."

Toribio on Wednesday refused to say whether he would seek the permanent job. "I'm very focused on moving forward with this department," he said. "We have started a lot of important initiatives and my focus is to carry out those initiatives."

Jordan, who rose through the ranks after joining the department in 1988 as a patrol officer, had two stints as police chief, both of which were marked by tragedy and controversy. His first tenure as interim chief in 2009 coincided with the shooting deaths of four officers by a parolee who was later killed by SWAT Team members. After replacing former Chief Anthony Batts in Oct. 2011, Jordan oversaw the bungled response to the first Occupy Oakland protest.

Frazier, then working as a city consultant, issued a scathing report of the police response to the protest. Jordan and other leaders were faulted for not having a plan in place or sufficient officers to handle the evening demonstrations that followed the early morning raid on the Occupy encampment outside City Hall.

More so than his predecessors, Jordan dealt with an understaffed police force that earlier this year had dwindled to its lowest level since 1996.

In Frazier's report on the Occupy Oakland response, Jordan was quoted saying that the department was "approaching crisis" and was "slowly grinding to a halt."

The city recorded 131 homicides last year, the most since 2006. Robberies jumped 29 percent last year and burglaries increased 43 percent. Oakland last year recorded the highest rate of robberies per residents of any major American city since 2000.

City leaders and former colleagues praised Jordan on Wednesday, citing his steely demeanor and dedication to the city. "Chief Jordan did a lot to try to bring the community and OPD together. That's no easy task," said Bishop Bob Jackson, pastor of Acts Full Gospel Church.

"He is an absolutely caring and dedicated person, loyal to the city and the police department," Dunbar said.

Reid said Jordan's departure was a loss for a department in search of stability in the face of increased federal oversight. "We take three steps forward and then take 20 steps backward," he said.

In his farewell email, Jordan told staffers that the decision to retire was " difficult but necessary."

"Through my 24 years of wearing an OPD badge and uniform I have emulated the department's core values: Honesty, Respect and Integrity -- values I have observed in all of you," he wrote. "I know that you and the department will carry on these values to generations to come."

At age 47, Jordan is three years too young to qualify for the city's top pension classification, which would have netted him about 75 percent of his salary a year for the rest of his life. Jordan, who last year made about $276,000 in salary and another $100,000 in benefits, could potentially still qualify for a pension benefit that is nearly as generous, if he is approved for a medical-related retirement.

Staff writer Thomas Peele contributed to this story. Contact Matthew Artz at 510-208-6435.