Vice President Joe Biden, Henry Louis Gates, Jr., Cambridge Police Sgt. James Crowley and President Obama at the Rose Garden “beer summit, July 30, 2010

As voters delivered Barack Obama a historic second term on Election Day, the elegant denouement of one of the most memorable early episodes of his presidency played out almost unnoticed at a polling site in Cambridge, Mass.

A black man and a white police officer embraced and talked warmly. The black man was Henry Louis Gates Jr., the author, documentary filmmaker and Harvard scholar. The white man was James Crowley, the police sergeant who handcuffed Gates on the porch of his campus home in July 2009. The arrest was the culmination of a tense confrontation that unfolded when Crowley was dispatched to investigate after Gates and his driver were seen struggling to open the house’s front door. Prosecutors later dropped charges of disorderly conduct against Gates.

Dan Riviello, a spokesperson for the Cambridge Police, confirmed the  reunion. “They had a good conversation,” Riviello said. “Professor Gates was filming a spot for a PBS special on voting in America. Sergeant Crowley organizes the officers at polling places, so they reached out to him prior, to get his OK. They hugged and had a few words.” When asked whether Crowley showed up in person to ensure that everything went smoothly, Riviello replied,“Yes, and to see the professor.”

It wasn’t the first time that the paths of Gates and Crowley have crossed since their famous Rose Garden “beer summit” with President Obama and Vice President Joe Biden. “He and I have gotten to know each other and we have very friendly communication,” Gates said on NPR’s Fresh Air in July 2011. Gates told The New York Times Magazine that Crowley made a gift of the handcuffs used in the arrest during a meeting initiated by Crowley at Gates’ favorite pub in Cambridge. Gates has described the move as “a very kind, generous gesture … motivated by the spirit of reconciliation inspired by President Obama.” (Gates donated the handcuffs, which reportedly bear an etching of Crowley’s name, to the new National Museum of African American History and Culture that is expected to open at the Smithsonian in 2015.)

The president’s intervention would prove to be a rare exception to, and likely informed, his reticence to enter the fray on race-related controversies—or indeed, to mention race at all. He intensified the national focus on the case and attracted the ire of law enforcement ranks when, in answer to a reporter’s question at a primetime news conference, he said that Cambridge police had “acted stupidly” in arresting Gates, who he identified as a friend. He would later acknowledge that he could have “calibrated those words differently.” He phoned Crowley (who was reported to have taken the call at Tommy Doyle’s Irish Pub in Kendall Square) to apologize.

The White House meeting that followed apparently did much to defuse the discord that the president, in his own words, “helped contribute to ratcheting … up.”  “I began receiving hate mail and death threats after the arrest, and all that stopped after the summit,” Gates told The New York Times Style magazine in 2011. “I know that what Barack Obama did was brilliant,” he said on Fresh Air.

For years Gates has looked to genealogy for meaning, and in this episode of his life he made no exception. He told The Oprah Winfrey Show that he asked Crowley to take a DNA test and discovered that they are distant relations—both descended from a 4th-century Irish monarch. “Eight percent of the men in Ireland have our identical DNA, and we all descend from King Niall of the Nine Hostages. It was good to be the king—the guy slept with everybody in the kingdom,” he said.

Crowley, for his part, has kept a low profile. In a statement following an independent committee’s June 2010 review of the incident (which concluded that both parties missed opportunities to de-escalate the confrontation), Crowley asked for respect for his decision to put the event behind him. “I do not want my family to have to go through what they did last summer,” he said. In May, Crowley’s name appeared without fanfare on a press release listing officers and community members who were honored at a 2012 Cambridge Police awards ceremony.