Digital Underground May Face Prosecution : Rap: San Diego city attorney looks into charging the group for allegedly simulating sex acts during a concert.

Digital Underground, an Oakland-based rap group, may be prosecuted by the San Diego city attorney for allegedly simulating sex acts with inflatable dolls during a summer concert at the city’s Sports Arena, authorities say.

The Aug. 26 show involved members of the group, which may be guilty of “obscene conduct in a public place,” Dep. City Atty. Gretchen North said Thursday.

North said the case was submitted for prosecution by the vice unit of the San Diego Police Department, which alleged that three members of the band “simulated various forms of human sexual conduct” on stage--albeit with their clothes on--during a concert attended largely by minors.

If the case is not prosecuted--and that decision has not been made--it will be because the city attorney “has decided we can’t win,” North said. Recent, celebrated obscenity rulings went against prosecutors in cases involving the rap group 2 Live Crew and a Cincinnati art museum for an exhibition of Robert Mapplethorpe photos.

“Because of the complex of constitutional issues involved, and the lack of success prosecutors had in cases involving 2 Live Crew and Mapplethorpe, we’re conducting extensive legal research to assist us in determining whether we have a reasonable opportunity of conviction,” North added.

“It’s not accurate to say we’re leaning one way or the other. This is a sensitive, high-profile case. What 2 Live Crew did was verbal communication, and although these people (Digital Underground) had their clothes on, what they did was more graphic. We expect a final determination in the next week or so.”

Sgt. L. D. Martin said two members of the police vice unit stopped in at the Sports Arena, after receiving complaints from parents about recent shows. He called it part of a “general inspection” and said the concert “was way out of bounds.”

The Los Angeles manager of Digital Underground was unavailable for comment as were officials of the San Diego Sports Arena.