NEW YORK – The gunman who killed hip hop icon Jam Master Jay has never been identified, but he has what could be a telltale characteristic – a tattooed neck, according to a witness.

Randy Allen noted the mystery gunman’s tattoo in a story Sunday in the Daily News, marking what the newspaper called his first extensive interview about one of the hip hop world’s legendary unsolved slayings.

Jay, whose real name was Jason Mizell, was shot dead in his Queens studio on Oct. 30, 2002. Despite a lengthy investigation and substantial reward, the case has been stymied by uncooperative witnesses, investigators say.

Allen, Mizell’s business partner, told the Daily News he had cooperated completely with investigators and was furious that others had not. “This is a case that can be solved,” he said.

Allen’s name has surfaced repeatedly in the case, as has that of his sister, Lydia High. Reports from four years ago indicated police placed her in protective custody. Recently, her attorney said he had not heard from her in more than a year.

Allen told the newspaper he was in the 24/7 studio’s control room at the time of the shooting, while his sister was near the studio entrance.

Allen said she told him that after two gunmen ordered her to get down on the floor, she saw a man with a tattoo on his neck approach Mizell and fire. A first round injured another person; the second was blasted into Mizell’s head from point-blank range.

Working with rappers Joe “Run” Simmons and Darryl “DMC” McDaniels, Mizell manned the turntables on such 1980s rap classics as “King of Rock,” ”It’s Tricky” and a top-40 remake of Aerosmith’s “Walk This Way.”