Vin was a Human male of the 21st century who resided in San Francisco on Earth. Vin was a guard in Sanctuary District A in that city in 2024 when he was one of several staff taken hostage and held at the Processing Center during the Bell Riots.
Vin was an irrascible man who believed that residents of the Districts were there through failings of their own, and not society. His opinion gradually changed during the course of the riots when several residents were able to tell their stories and Gabriel Bell ultimately saved his life by preventing authorities from shooting him during their attempt to retake the Center.
Vin was played by actor Dick Miller. He was named after Steve McQueen's character of Vin in the film The Magnificent Seven. (Star Trek: Deep Space Nine Companion, p. 197) Dick Miller's costume was auctioned off in the It's A Wrap! sale and auction.
An interesting tie-in fact is that, if Vin had lived in San Francisco his whole life, he would have been in his late 20s or early 30s during the events seen in Star Trek IV: The Voyage Home. In this case he would have been a child during O'Brien and Kira's brief visit to 1967 in "Past Tense, Part II".