Assistant police chief Jim Pugel, who will replace retiring police chief John Diaz as interim chief at the end of May.

Embattled Seattle Police Chief John Diaz, a 36-year veteran of the department, announced this morning that he will retire at the end of May; his interim replacement will be Assistant Police Chief Jim Pugel, who heads up SPD's criminal investigations division. 

Saying he had promised his wife he would retire "sometime this year," Diaz said this morning that he had wanted to wait until the Department of Justice investigation into allegations of racially biased policing and excessive use of force was complete and a federal monitor to oversee the police department's reform efforts was in place. 

"I had planned that I was going to retire one way or another sometime this year," Diaz said. It’s been a ... long time in the breach [but] I don’t leave a fight. I wanted to make sure that the reform effort was well on its way" before stepping down, he said.

"This is the time to go," Diaz added. "Is there ever a perfect time? No, but this was the right time for me. ... Once I knew that the monitoring plan was in place, that was the last piece of the puzzle."

Mayor Mike McGinn appointed Diaz, who is 55, permanent police chief over several other candidates in 2010; previously, he had served as interim police chief and was deputy police chief for nine years. 

During his years as police chief, Diaz presided over several incidents involving alleged excessive use of force by police officers and repeated allegations of racially biased policing, which culminated in a Department of Justice finding that SPD engaged in excessive force and the appointment of a federal monitor to oversee police reform. 

Additionally, last week, an outside review board found that the police department had inadequately prepared for last year's May Day protests, which resulted in widespread vandalism, violence, and allegations of police brutality.

McGinn and Diaz said those incidents had no bearing on the chief's decision to leave. 

"It’s no secret to everyone that it’s been a challenging and turbulent time for this police department, but this chief has led the way for a new generation of leaders and he now passes the baton," McGinn said. He said he had not tried to talk Diaz out of his decision. "I'm not going to begrudge anyone the right to say they're done."

The news takes the wind out of McGinn opponent Tim Burgess' vow to fire Diaz if he's elected mayor. 

McGinn said he would begin the process of looking for a new chief, but that the actual appointment "won't be made until well after November anyway." Pugel said he hadn't decided yet whether he'd seek the permanent chief position.