OAKLAND -- The Police Department soon may "cross the finish line" in its 11-year effort to complete court-mandated reforms, but judicial oversight is likely to continue for some time, the department's powerful overseer wrote Monday.

In his bimonthly progress report, Robert Warshaw cautioned that Oakland's Police Department "still has much work to do to institutionalize" reforms aimed at improving accountability and preventing discriminatory policing. "The court," he wrote, "will not likely vacate this process until there is demonstrated evidence of sustainable reform."

Warshaw also expressed concern about a recent police report showing that African-Americans are far more likely to be pulled over and searched by Oakland police than other residents.

Oakland's reform effort began in 2003 following the Riders police brutality scandal, in which four officers were accused of beating up and framing drug suspects in West Oakland.

Warshaw, a former police chief in Rochester, New York, who has been monitoring Oakland police since 2010, was granted sweeping powers by a federal judge earlier this year to get the department into full compliance. The city pays Warshaw's consulting firms a total of more than $1 million per year to oversee the department.

After several critical reports, Warshaw has noted significant progress this year. The department currently is not in full compliance with only six of the original 51 reform tasks, Warshaw wrote Monday.

He credited city and police leadership for recent gains and noted that Chief Sean Whent personally teaches new members about the process for reporting misconduct in the ranks.

Warshaw, however, expressed concern over a recent department report showing that African-Americans, who comprise 28 percent of Oakland residents, accounted for 62 percent of police stops from last April to November. That report also showed that African-Americans were more likely to be searched, although those searches were no more likely to turn up guns or drugs.

While Whent defended the figures, noting earlier this year that police have been focusing their efforts on the most violent sections of the city, Warshaw wrote Monday that he would be discussing "strategies to resolve the disparities" in the report. "Biased-based policing in Oakland," he wrote, "remains an issue that we must continue to address."

The department has hired Stanford University professor Jennifer Eberhardt to review and map data from police stops.

In a prepared statement Monday, Whent acknowledged the more work was needed to complete the reform drive. "We remain dedicated to achieving organizational excellence," he said. "We will continue to partner with all stakeholders as we move forward with this important work."

Contact Matthew Artz at 510-208-6435.