Philadelphia Deputy Police Commissioner Joseph P. Sullivan resigned Friday, 10 days before a new top cop is set to take over the department.

Sullivan, who joined the department in 1982, confirmed his departure in a text message Friday evening, calling it effective immediately but declining to comment further.

Danielle Outlaw, the former chief of police in Portland, Ore., will begin her tenure as Philadelphia’s new police commissioner on Feb. 10. Sullivan was interviewed for the job during Mayor Jim Kenney’s search process following the August resignation of Richard Ross.

It was not clear what role Sullivan might have had in Outlaw’s administration.

Inspector Sekou Kinebrew, a department spokesperson, declined to comment Friday, and Acting Commissioner Christine M. Coulter did not respond to requests for comment.

A Philadelphia native and the son of a civilian employee of the Police Department, Sullivan was named a deputy commissioner — the second-highest rank in the 6,500-member department — in 2017 and placed in charge of patrol operations. At the time of his promotion, Ross called him a “tactical genius.” He was paid an annual salary of $208,000, according to payroll records.

Sullivan became widely known several years earlier, when, as a chief inspector, he oversaw the department’s response to a variety of large-scale events, including frequent protests, the visit by Pope Francis in 2015, and the Democratic National Convention in 2016.

In 2016, he was awarded the Richardson Dilworth Award for Distinguished Public Service, the city’s most prestigious honor for public employees.

That year, he was reportedly under consideration to become police chief in Memphis, Tenn.

His departure leaves Outlaw with three active deputies, down from five when Ross was in charge. In addition to Sullivan’s departure, former first deputy Myron Patterson is using up his vacation time in order to retire.

Two other deputies — Dennis Wilson and Robin Wimberly — are enrolled in the Deferred Retirement Option Plan (DROP), meaning they are set to retire within the next four years.

Coulter, meanwhile, has been acting commissioner since Ross stepped down amid claims in a lawsuit that he retaliated against a former love interest. Ross has denied the allegations.

Coulter interviewed to keep the top cop job permanently. It’s not clear what role she might play when Outlaw takes over.