Back in the day, Cope2, a Bronx graffiti legend as big as a linebacker, usually found himself in proximity to police officers only when they were tracking him in the metallic darkness of a subway yard or when they finally caught up to him and hauled him in.

But on Thursday night he sat willingly within reach of three officers — or at least three retired ones — on a comfortable couch at the powerHouse Arena, an art gallery and bookstore in the Dumbo section of Brooklyn. The officers, one of whom had arrested Cope2 several years earlier when he was leaving his house to walk his pit bulls, sat on another couch across from him and two fellow graffiti artists.

For the next hour and a half, in front of a packed room, all six were guests on a kind of bizarre hip-hop “Dick Cavett Show,” featuring profanity, accusations of police brutality and lots of memories from the days when both the artists and officers were younger and more agile, fully enlisted in the cat-and-mouse game of New York City graffiti in its heyday.

The event was occasioned by the publication of “Vandal Squad: Inside the New York City Transit Police Department, 1984-2004,” by Joseph Rivera, a veteran anti-graffiti officer who retired from the force in 2004 and has written perhaps the only book to look at the graffiti movement from the law enforcement perspective. But the book, which was issued late last year by powerHouse Books and is lavishly illustrated with pictures and resembles a lot of publications that celebrate graffiti, has come in for heavy criticism from some of the artists mentioned in it, who complain that Mr. Rivera is simply trying to cash in now on an urban phenomenon that he spent his career vilifying.