The journey of Michael Patten — from walking a beat by Silliman and Timothy Dwight Colleges, to heading the Yale Police Department’s patrol operations as assistant chief — began 25 years ago, when New Haven was a very different town.

Crime rates ran high, and the incidence of robberies around Yale’s campus was roughly double what it is today. But for Patten, who retired from the police force earlier this month, policing the campus has been about much more than reducing crime.

“It’s all about the relationships,” Patten said. “There were a lot of significant incidents that happened in the last 25 years — two homicides, two bombings, two dignitary visits. But the thing that stands out most in my mind is the people I met.”

In 2011, YPD Chief Ronnell Higgins — whom Patten supervised as a sergeant in the 1990s — appointed Patten to assistant chief during a larger departmental reorganization. In that new role, Patten oversaw YPD’s car, bicycle, motorcycle and foot patrols, as well as YPD’s dispatch center and emergency services.

“Losing someone like Mike, who had an encyclopedia-type knowledge of the campus and our policies, is a big loss,” Higgins said. “But one thing Mike did over the last 24 months is develop subordinates in key areas. It’s time for them to step up and step in.”

Patten retires after over 40 years of policing: He came to Yale after working for the Amtrak Police Department in Connecticut and New York. Through the YPD, Patten met former U.S. presidents, Supreme Court justices and monarchs. Policing always presented new faces as well as new challenges to Patten, such as when YPD had to create a new counterterrorism team following the Sept. 11 attacks.

During Patten’s time at Yale, the campus was also rocked by the separate homicide deaths of two students. Patten said the police department had a central role in responding at the crime scene and providing resources to the broader community while they dealt with the loss.

“I’ve always found that when people have problems, even when you can’t do anything, you have to be responsive,” Patten said.

He said the biggest change during his tenure has been the use of technology — cell phones, laptops, surveillance cameras and swipe cards — in public safety efforts. But even so, he said, personal relationships have remained central to his work. When he arrived at Yale, Patten attended monthly residential college council meetings and knew each head of college and dean by name.

“[Cell phones] are how people communicate with each other now … but it still comes down to personal relationships,” Patten said.

Higgins said that as New Haven has become safer through the work of the New Haven Police Department, so have Yale students begun to engage more in the city.

But all good things come to an end, and Patten told Higgins in the fall of 2015 that he was considering retirement. After Patten officially retired earlier this month, Higgins decided to relegate the responsibilities of Patten’s position to two YPD captains, who will be promoted to their new roles later this week.

Assistant Chief Steve Woznyk, who was appointed the same year as Patten, will continue in his position.

“We are stewards of the Yale Police Department. One day I won’t be here, just as one day Mike decided to retire,” Higgins said. “The success of this department is dependent on the men and women on the front lines.”