“It was very hard sitting there and listening to all the lies,” Officer Morales said afterward.

Officer Kern, whose confident, matter-of-fact testimony was a key part of the defense case, showed no expression before the verdict was read, then smiled, hugging his lawyer and his parents, who sobbed at news of the outcome.

Afterward, he said he hoped to “get back on the street and do what I love to do: protect the people of Brooklyn.”

Mr. Miller, the juror, said prosecutors never answered critical questions, like why there was no blood on the jeans Mr. Mineo was wearing during the confrontation. The jury asked the judge to play surveillance video from the day of the arrest in court. Though Mr. Mineo and another witness had testified that he had blood on his hand, jurors saw him place his hands in his pockets in the video and they asked to examine the jeans on their own. They found no blood in the pockets or the seat, Mr. Miller said. The jurors, Mr. Miller said, were also troubled by a hole in Mr. Mineo’s boxers: He said it was caused by the baton, but expert witnesses presented by the defense said that was impossible.

The prosecutors, Mr. Miller said, “were never able to answer how the hole was made.”

As soon as Mr. Mineo’s allegations emerged in 2008, they drew comparisons with the 1997 torture of Abner Louima, a Haitian immigrant who was sodomized with a broomstick by a police officer in Brooklyn’s 70th Precinct station house. The Louima attack became a national symbol of police brutality and racism, and the main officer involved was sentenced to 30 years in prison.

But while Mr. Louima’s injuries, including punctured internal organs and missing teeth, strongly suggested an attack, Mr. Mineo’s medical condition was more murky: His lawyers said he had developed an abscess, but they initially refused to release his medical records.

And while the attack on Mr. Louima by a white officer stirred longstanding complaints about the treatment of black men by the police, there was no racial component to Mr. Mineo’s case, since both he and the officers involved were white and Hispanic. It spawned neither major civil rights protests nor sweeping change to training or operations within the ranks. As the trial got under way in State Supreme Court in Brooklyn last month, there were neither protests outside the courthouse to support Mr. Mineo nor a sea of blue uniforms inside to support the officers.

Image Officer Richard Kern, center, facing the camera, and Officer Alex Cruz, who had been charged with a cover-up of police abuse. Credit... Kirsten Luce for The New York Times

Throughout, the defense made diminishing Mr. Mineo’s credibility a priority, telling jurors about his drug use, previous arrests and the federal civil rights lawsuit he filed against the city, seeking about $350 million in damages. (Mr. Louima won about $8 million in settlements).