There are few matters that can embroil a neighborhood like a bar fight. And one in Adams Morgan between residents and a nightclub along 18th Street is no longer confined to the angry players staking out each side.

Dragged smack into the middle is one group that tries to stay neutral and moderate tensions: D.C. police.

Two officers found themselves in an uncomfortable spot Wednesday when faced with seemingly contradictory orders at a hearing of the liquor board. Should the veteran captain and less-senior sergeant testify for the bar owner, who had served them with subpoenas, or listen to their boss, who, it appeared, ordered them to stay silent?

The protagonists were set to square off on whether Club Timehri’s license should have its license renewed and be permitted to expand its hours. A stabbing there in 2012 prompted authorities to shutter the club for 10 days and levy $4,000 in fines.

A group representing Kalorama neighbors objected to the club’s requests. The club owner hoped the officers would say that the bar has been responsible — and help persuade the liquor board to side with the bar.

At the hearing, the sergeant told the Alcoholic Beverage Control Board that he was not allowed to answer questions. The captain testified, but the attorney for the club complained that his statements fell short of the full support promised before the edict from command came down.

“Clearly they were influenced,” said the attorney, Andrew J. Kline, who accused an assistant D.C. police chief of ordering her officers to disobey a subpoena. “I spoke to both witnesses. I knew what they were going to say. One wouldn’t testify, and the other changed his story dramatically.”

The backdrop of this testy dispute is the surging nightlife that attracts thousands of young, bar-hopping revelers to the 18th Street strip that abuts some of the District’s most expensive real estate. Clashes over noise and drunkenness are frequent, and police are trapped trying to find common ground as they enforce the law and moderate behavior.

As this case suggests, it is no easy task.

Through a public-records request, Kline obtained e-mail exchanges involving Diane Groomes, the assistant chief of patrol, and Denis James, president of the Kalorama Citizens Association, in which he complained that police appeared to be supporting business interests over the residents’ objection. Groomes responded six minutes later, bringing the officers’ commander into the loop, writing: “No ofc shall testify at such hearing.”

Kline accused Groomes of interfering with an independent hearing. “We expected the officers to get on the stand and tell the truth,” he said, adding that they can testify “truthfully, concerning facts” without testifying “for” or “against” a person.

James said he grew concerned when he saw the officers’ names on a witness list, which he said did not indicate that they had been subpoenaed. He e-mailed Groomes: “The last thing this community or MPD needs is to be seen as the servant of a business that brings violence to our community.”

In an interview, James said, “If someone is putting on a witness, the feeling is that it is favorable to their side.”

The alcohol board hasn’t made a decision on the club’s license or hours. It issued the subpoenas at Kline’s request, and a spokesman said the attorney could request that the board “take steps to require” the one officer to testify by going to a judge.

Groomes said in an interview she did not know that the officers had been subpoenaed when she sent her e-mails. She also said she informed James that she could not forbid the officers from testifying if they had been subpoenaed.

The assistant chief said she wants to avoid the perception that officers take sides. “We are a neutral party and should only relate to public-safety issues,” she said. Testimony at such hearings, she said, should be made by commanders or chiefs. “We can speak on behalf of the agency,” Groomes said.

In the end, Groomes’s attempt to keep her officers out of the fray ended with the Kalorama association and the club complaining that at one point or another, the police had taken their side and then switched positions.

It’s exactly what Groomes tried to avoid.

“I don’t want them saying that this club is dangerous,” she said, “or that this club is the best thing ever.”

Mike DeBonis contributed to this report.