The mob-like murder of 61-year-old Seattle labor leader Mario Vaccarino—his body found seasoned with Parmesan cheese and floating face-down in his bathtub—is now among half a dozen possibly related cold cases from the 1970s and 1980s that have heated up again. They include dead bar owners and associates who were in competition with convicted racketeer and exotic-dance kingpin Frank Colacurcio Sr.

“We’re reviewing all those cases,” says King County Sheriff’s Detective Scott Tompkins, whose cold-case team has worked with a Seattle and federal task force but is pursing the union case separately. “Vaccarino’s death is one we’re actively trying to solve.”

Investigators were recently told that a former Colacurcio associate claims Vaccarino, head of Hotel and Restaurant Employees union Local 8, was killed Oct. 24, 1985 by a man now serving life in prison for another murder. However, the associate never indicated that Colacurcio was involved, and the 91-year-old strip-club magnate has not been charged and has denied any involvement. (Federal investigators are currently probing Colacurcio’s four nude-dance club businesses for alleged “promotion and facilitation of prostitution,” the FBI says in court papers.)

The killer reportedly was told to rough up Vaccarino, but took it too far. He ended up putting the body in the tub and sprinkling it with Parmesan to suggest it was an Italian mob killing, the associate said. But the killer’s identity, and who hired him, remain a mystery, and in the past the trail has actually led away from Colacurcio, to the union’s international headquarters and elsewhere.

“What we’re learning,” a police investigator said at the time of Vaccarino’s death, “is that there are 50 people with a motive for killing him.”

Among other cold cases being probed is the 1975 slaying of strip-club owner Frank “Sharkey” Hinkley and his fiancée, Barbara Rosenfield, at Hinkley’s Bear Cave, a club once located near Boeing Field. One man, James Braman Jr., was charged with the killings, in part to force him to cooperate with investigators. But after refusing to talk—”He said `They’ll kill me if I do,'” recalls Tompkins—Braman eventually killed himself in 2006 with an overdose of methadone.

One of these cold cases has been solved: the 1978 contract killing of Leroy Grant. The hitwoman, Karen L. Martin, is now serving 20 years in prison, and admitted in 2007 that she was hired to kill Grant by someone connected to a local mob. Grant had obtained money “he wasn’t supposed to have,” said Martin, who claims never to have received the $10,000 she was promised for the hit.