By Nick Valencia and Kaylee Hartung

CNN

(CNN) -- The top cop in the Baton Rouge Police Department submitted his letter of retirement to the city's mayor on Monday, marking the second time a high-profile cop has stepped down in Louisiana's capital city since the summer 2016 shooting death of Alton Sterling.

"Unfortunately, I am in a situation that will not serve our police department or the citizens of Baton Rouge," police Chief Carl Dabadie said in an official statement announcing his retirement. "My hope is that the men and women of the Baton Rouge Police Department will be allowed to perform their jobs according to state law, without prejudice, and that politics will not prevail over public safety."

The move was expected by some in Baton Rouge, because Mayor-President Sharon Weston Broome had hinted about a change in leadership since the start of her term in January.

In fact, one of Broome's main campaign promises during her run for mayor in late 2016 was to replace the city's police chief.

Dabadie appeared to address their strained relationship in his retirement letter to the mayor.

"I had hoped our relationship could have grown into a strong partnership as we have faced times this city has never seen," Dabadie said of Broome, according to the Advocate newspaper. "I feel that my retirement would be the best thing for the department and myself."

The mayor's vow to change local police leadership came on the heels of the police shooting death of Alton Sterling on July 5, 2016.

A source close to the situation said Dabadie's retirement had been part of negotiations with the mayor for months.

"[The mayor] came to the realization early on that in order for the community to have faith in the [police] department there needed to be a change in leadership," the source told CNN. "The community has had an incredible amount of distrust in the Baton Rouge Police Department since last year."

Sterling, a 37-year-old black man, was shot and killed during a struggle with two white police officers outside a convenience store last summer.

In the days after Sterling's death, the city descended into unrest, with mass demonstrations and over 100 arrests. Many called for the removal of Dabadie as police chief.

"[The mayor] had nothing against him personally, but the dialogue about this move has been going on for quite some time," the source added.

In a statement to the media, Broome thanked Dabadie for his service.

"I wish him the best in all of his future endeavors," the mayor said.

Dabadie served the Baton Rouge police for more than 30 years and was appointed chief in 2013. He called the past year "the worst year we have experienced during my time as chief" in his statement. It was a year that included the highly publicized shooting of Sterling, shortly followed by the slayings of three Baton Rouge area law enforcement officers.

The move also comes four months after the abrupt retirement of Louisiana State Police Col. Mike Edmonson.

"[Edmonson's retirement] had nothing to do with social justice. In fact his leadership and the way the state police was involved with the local community was seen as a model for the way BRPD should interact with locals," a source close to the situation told CNN.

Edmonson was replaced by Superintendent Kevin Reeves.

Broome said a national search for a permanent police chief in Baton Rouge is underway.

There is still uncertainty among locals regarding the Sterling shooting investigation.

In May, the Department of Justice decided against pursing civil rights charges against Blane Salamoni and Howie Lake, the two officers involved in Sterling's shooting death. However, there is still a pending investigation by Louisiana Attorney General Jeff Landry as to whether to pursue criminal charges against the officers.

There has been no timetable given for that announcement.

"There's been a lot of movement this year," a source close to the situation said, referring to the changes in law enforcement leadership. "Now the real work begins."