DALLAS — Chief David Brown was the longest serving Dallas police chief in decades.

For six years, he lead more than 3,400 officers.

"There is a lot of good that came out of this relationship but also a lot of turmoil," said Fred Frazier, of the Dallas Police Association.

He has been lauded for strengthening community-based policing and putting in place reforms to reduce confrontations between police officers and the community. He's also allowed for more transparency in police involved shootings.

"Under his leadership, we have also done it the right way reducing deadly force dramatically and issuing body cameras for a thousand officers," said Mayor Mike Rawlings.

But the chief hit turbulence with the Police Associations who not once but twice called for him to step down.

At a news conference earlier this year, before the July ambush, they had harsh words for him.

Then DPA President Ron Pinkston said,"We all work under the chief and he's a vindictive chief."

This year, the department has struggled with increasing response times, a rising crime rate and officers retiring in record breaking numbers due in part to low pay and a failing pension system.

Tuesday, dozens of officers retired alongside the chief amid the turmoil which some blame more on the city council than the chief.

"We never fixed the pay problem so we never fixed the problem with the officers," Frazier said.

Then came, July 7, which changed the face of the Dallas Police Department and the city forever. On that day, five officers were ambushed and killed.

Chief Brown was widely praised for his strength during that difficult time.

"He did an excellent job on bringing the department back together at the time we needed a strong leader," said Sheldon Smith, with the Black Police Association of Greater Dallas.

Chief Brown said during a recent news conference that it was simply time for him to go.

"I have no regrets," he said. "I've accomplished what I set out to accomplish as a 22-year-old from Oak Cliff to serve my community. I'm retiring with satisfaction that I made my mom proud of me."

Brown has not announced what he will do next but did say he plans to spend more time with his wife.

First Asst. Chief David Pughes has been named interim chief until the city does a nationwide search to hire the next chief.