A retired police officer has been charged with four counts of murder in what the authorities called the “gangland-style” killings in April of four men in a Hudson Valley bar in connection with a cocaine-distribution conspiracy.

The retired officer, Nicholas Tartaglione, 49, who worked for the Briarcliff Manor department in Westchester County, N.Y., was arrested on Monday and charged in the four killings, the federal authorities announced in a news release.

“While all murders tear at the fabric of our communities, when the alleged perpetrator of a gangland-style, quadruple homicide is a former police officer, that strikes at the heart of civilized society,” Preet Bharara, the United States attorney for the Southern District of New York, said in a statement.

Beyond saying that the four men — Hector Gutierrez, Martin Luna, Miguel Luna and Urbano Santiago — had been killed “in and around” the Likquid Lounge in Chester, N.Y., in April, the authorities released few other details about the murders.

It was unclear what role, if any, they had in the cocaine-distribution ring that Mr. Tartaglione is accused of participating in. Some of the men, according to the news release, were in “the wrong place at…