Stonington — Detective John Fiore has retired after 37 years on the force and has moved on to take a job as a police officer with the Mohegan Tribal Police department.

Fiore celebrated his last day two weeks ago with a low-key lunchtime gathering at the department that featured pizza and stories from officers past and present.

He said last week that police officers know when it’s time to retire.

“It struck me as being time to do something different,” he said.

“We’re certainly going to miss him. A lot of knowledge just walked out the door,” said Chief J. Darren Stewart, who worked with Fiore on third shift when he joined the force 32 years ago.

“John has been a fixture here for 37 years. He’s worked on a lot of big cases and has done a great job for us,” Stewart said.

“But he’s not giving up police work. He’s just changing uniforms,” he added.

He called Fiore an excellent report writer and accident reconstructionist who has 50 letters of thanks from citizens in his file.

He will be replaced in the detective division by veteran Officer Greg Howard, who was part of the department’s first K-9 team.

Over his nearly four decades with the department, Fiore said the aspect of the job that has changed the most is how officers conduct their investigations.

“A lot of what we do now is electronic,” he said. “Social media is a huge investigative tool because people don’t think about what they’re putting out there.”

He added that drug laws have changed and there is not as much underaged drinking and driving as there once was.

Fiore said he will miss his colleagues.

He especially singled out his partner, veteran Detective Cody Floyd.

“He is the best investigator I will ever know,” he said.

Fiore, who performed accident reconstructions for 15 years, said the one thing he will not miss is the fatal crashes he had to respond to and investigate.

“If I have any bad memories, it’s of those,” he said.

Fiore said law enforcement at the Mohegan Sun casino is “way different” than working in Stonington.

“You do a lot of walking here,” he said. “It’s so massive.”

Fiore said former Stonington Officer Randy Holt, who now works for the tribal police department, has been helping train him.

“I trained him when he started. We’ve come full circle,” he said.

j.wojtas@theday.com

Twitter: @joewojtas