Seattle police are increasingly likely to miss a deadline for a crucial reform plank requiring adequate staffing of critical front-line sergeants, the federal monitor overseeing court-ordered changes has warned the department in a bluntly worded letter.

Under a consent decree between the city and Department of Justice (DOJ), supervision at the sergeant level is considered a key element in curtailing excessive use of force uncovered by the DOJ.

The Police Department is required to ensure that field officers are assigned to a single, consistent sergeant; to decrease the use of acting sergeants; and to deploy enough sergeants to properly supervise officers, particularly to investigate and document use of force.

While the department has made laudable strides on the first two matters and is poised to meet a June 30 deadline for partial compliance, it has failed to adequately address the third prong, the monitor, Merrick Bobb, wrote in May 5 letter to Assistant Chief Mike Washburn obtained by The Seattle Times.

Save 75% on a Digital Subscription Today

The department’s most recent plan “does not adequately detail exactly how the Department will come into compliance” with the provision of the consent decree “mandating that enough sergeants be engaged to guarantee adequate supervision of SPD officers — often referred to as ‘Span of Control,’ ” Bobb wrote.

Bobb sent the letter about a month after the federal judge supervising the settlement agreement, James Robart, chastised the city at a court hearing over missed deadlines and mismanagement.

Robart said there would be no further changes to deadlines without his approval.

Bobb’s letter says it appears unlikely the Police Department will be in compliance with the third prong by June 30, and reminds the department it will need to petition the court for an extension if that is the case.

The letter lists a litany of deficiencies, citing a lack of details on personnel to carry out the plan, how objectives will be met and who will determine workload and ratios of sergeants to officers.

Also lacking is analysis to determine how personnel should be allocated and redeployed, Bobb wrote.

Police spokesman Andrew Garber said the department was crafting a response letter and, for now, wouldn’t comment on Bobb’s letter.

Bobb’s letter states that the department was originally supposed to craft a detailed report on meeting all the sergeant requirements by the end of last year and to be in compliance by June 30.

But the department produced a five-page document that was inadequate and listed an “undefined timetable sometime in 2015,” the letter said.

The department was under a different command structure at that time, which was replaced in January by a new one.

An updated work plan submitted on Feb. 28 was “insufficiently precise, detailed, responsive, and rigorous,” with deadlines in a “protracted time horizon,” the letter said.

The department produced an improved plan March 21, yet remained insufficiently detailed with a vague timetable for reaching partial compliance with all the sergeant requirements, Bobb wrote.

A fourth version offered April 16 represented a “noteworthy improvement, ” the letter said, stating for the first time the department could comply on June 30 with the provisions regarding acting sergeants and consistent assignments.

But it fell short on the third prong, Bobb wrote.

A new police chief, to be announced Monday, will inherit the issue if confirmed by the City Council.

Steve Miletich: 206-464-3302 or On Twitter @stevemiletich