Chappaqua, N.Y., sits some 40 miles to the north of New York City. Population-wise, it is a blip on the map next to the urban behemoth. Chappaqua’s residents numbered just nearly 1,200 in 2014, according to an estimate from the Census Bureau. But what the hamlet lacks in density it more than makes up for in prosperity, with the median 2015 home valued in the ballpark of $1.2 million. Chappaqua boasts several famous residents, too: Democratic presidential nominee Hillary Clinton and her husband, Bill, have a house there, as does actor Ben Stiller.

Early Monday morning, buckshot blasts from a shotgun pierced a delicatessen door, shattering with it Chappaqua’s well-heeled tranquility.

Two men were wounded. The identity of one man has not been released, but the other — Dennis S. Charney, the dean at Mount Sinai’s Icahn School of Medicine in Manhattan — appeared to be the target.

The man who fired the gun, according to police, was Hengjun Chao, a 49-year-old former scientist who worked at the New York City medical school from 2002 until he was terminated in 2010.

The motivation for the alleged attack, authorities said, is thought to be revenge.

If so, it is a plot years in the making.

In September 2007, then-assistant professor Chao apparently soured on the relationship with one of the postdoctoral fellows in his lab, Ellen Cohn, with whom he had previously published genetic research in Nature and other journals. Chao argued that Cohn fabricated scientific data — a huge ethical breach — according to a copy of Mount Sinai’s internal report published at Retraction Watch. The school’s early investigation into Chao’s allegations, however, turned up empty.

A month later, Cohn claimed that it had been Chao who pressured her to alter experimental results.

Cohn accused Chao of “multiple counts of research data fabrication, research data manipulation, and intentional or reckless disregard of research data/recordings.” For instance, she said he directed her to report that lab mice had died after a certain viral therapy. In fact, the animals were still alive.

Over the next year, a committee of five professors interviewed Chao and found him to be “defensive, remarkably ignorant about the details of his protocol and the specifics of his raw data, and cavalier with his selective memory.” Though the inquiry panel was not able to find proof for each of Cohn’s allegations, there was enough evidence that the school concluded Chao had “promoted a laboratory culture of misconduct and authoritarianism.”

In May 2009, Charney, as Mount Sinai’s dean, terminated Chao per the committee’s conclusions. (Cohn, meanwhile, voluntarily resigned.) Chao then unsuccessfully sought to use various procedures and appeals within the medical school to be reinstated. Having exhausted those, he filed suit in federal court, where he lost in both federal district court and before the U.S. Court of Appeals for the 2nd Circuit.

Years later, the workplace conflict appears to have flared up again, this time violently.

Around 7 a.m. on Aug. 29, Charney left Lange’s Little Store & Deli in downtown Chappaqua, a favorite morning grub spot among locals and Bill Clinton. As the medical school dean walked along the sidewalk, shotgun pellets struck him, according to a press release issued by the New Castle, N.Y., police department on Tuesday. Buckshot also passed into the deli, wounding a second man. Police arrested Chao in a nearby parking lot, discovering a loaded Mossberg 500 shotgun in his car.

The gunfire took Chappaqua residents by surprise — initially, a few locals believed the shotgun sounds somehow involved the Clintons, or they dismissed it as a movie shoot, according to the Journal News. Both Charney, 65, and the other injured man, 56, were taken to Westchester Medical Center. As of Tuesday, the unnamed victim had been released. Charney was being treated for non-life-threatening injuries, according to the police news release.

“This is an extremely disturbing event,” Kenneth L. Davis, Mount Sinai Health System’s chief executive, said in a statement to the New York Times. “Fortunately, Dr. Charney’s injuries are not life-threatening, and we expect he will fully recover.”

John Guarino (no relation to this reporter), a longtime customer of Lange’s and a retired police officer, told the Journal News on Tuesday that revenge is not uncommon but opening fire on a deli with a shotgun is “pushing it.”

“Guys go nuts if they felt they’ve been wronged,” Guarino said, “it goes to show you can’t even go for breakfast anymore without worrying.”

The New Castle police said in its statement that Chao knows Charney, and according to the preliminary investigation, the dean was “the intended victim of the shooting.” Of Chao, “I think he came up here intent on shooting someone,” New Castle Police Chief Charles Ferry said on Monday, according to CBS New York. Chao also appeared to know Charney would be at the deli, leading investigators to believe the man had been spying on his former boss.

New Castle Justice Noah Sorkin remanded Chao to Westchester County Jail without bail, according to the New Castle police. Chao is set to appear in court in early September. It was unclear as of Tuesday whether Chao has a lawyer or has entered a plea yet.