SEAL BEACH — Police Chief Joe Stilinovich turned in his resignation Friday following a five-month investigation by the city into alleged “serious misconduct.”

In a joint statement, Stilinovich and City Manager Jill Ingram announced “his resignation from city service effective immediately.”

The reason for Stilinovich’s resignation was not disclosed. He was put on paid administrative leave in October.

“This is a confidential personnel matter and we cannot say anything more at this time,” the brief statement said.

Cmdr. Joe Miller will continue to serve as interim chief of police, according to the statement.

Councilwoman Ellery Deaton said she thanked Stilinovich for his service to the city, but declined to offer further comment.

“At this point, it is important to both honor his decision and respect his privacy by allowing him to comment as he sees fit on his decision to resign,” she said Friday.

Stilinovich’s departure caps a small-town drama that endured for nearly half a year. During his four-year tenure, the police chief gained a fan base that continued to support him throughout the investigation.

In early October, the city announced that Stilinovich had been put on leave pending the investigation of a formal complaint of “serious misconduct.” Within days, hundreds of residents were calling for his return and signing petitions.

Messages to “Chief Joe” filled a banner hung near the pier. Dozens of people gathered for a rally.

And at least a handful of residents showed up at every City Council meeting, holding “I support Chief Joe” signs, to criticize Ingram for the long investigation process.

“Chief Joe was a dynamic force in the community and we are going to miss his leadership,” Tom Stretz, president of the Seal Beach Police Foundation, said Friday. “He was uniquely visible and effective. He gave a face to community policing.”

Although they speak frequently, Stretz said Stilinovich is “the consummate professional” who never divulged details of the allegations. Nor did Stilinovich elaborate on his decision to resign.

“The whole thing had to wear him down,” Stretz said. “But he’s not the kind to be pressured into doing something he doesn’t want to do. He feels this is the best thing for himself, his family and his career.”