SAN ANTONIO (AP) _ Prosecutors dropped criminal charges Monday against a record store owner who sold the 2 Live Crew album ''As Nasty As They Wanna Be,'' saying they couldn't prove the sexually explicit lyrics were obscene.

Dave Risher's trial was about to begin when Bexar County Court-At-Law Judge Tony Jimenez III dismissed the charges at the prosecutors' request. He also asked sternly why it took them six months to come up empty-handed.

''I think that the (district attorney's) office owes Mr. Risher an apology,'' he said. When he dismissed the court, spectators clapped and cheered.

Risher was charged after Patrick Weaver, son of the president of Citizens Against Pornography, bought the album at Hogwild Records and Tapes in June and then complained to police it was obscene. The album includes references to oral and anal sex and sexual violence against women.

The case apparently fell apart when Weaver listened to the album last Friday with the prosecutors and decided it didn't violate state obscenity laws. Expert witnesses also told prosecutors they weren't sure the rap album's contents met the state's test for obscenity.

''Taken as a whole, he (Weaver) did not feel that this album was obscene,'' Hancock said afterward. ''That is a weakness in our case. We obviously felt that trying the case would have been an injustice.''

Among other criteria, material can only be called obscene in Texas if it is found by a reasonable person to be without literary, artistic or political value.

Weaver, 20, declined to be interviewed later. But his mother, Teresa Weaver, said in a call to their home that ''as much as he wanted to address was already addressed.''

''I thought we were going to trial today. I'm pleasantly surprised,'' said Risher, who had been charged with promotion of pornography. The misdemeanor carries a maximum penalty of a year in prison and a $1,000 fine.

''I can't wait to get back to work,'' said Risher, owner of Hogwild Records and Tapes.

Risher was charged after San Antonio vice officers visited record stores and told owners that a federal judge in Florida had found the album obscene. After that ruling, a Fort Lauderdale, Fla., record owner was convicted of a misdemeanor obscenity charge. Members of the Miami-based rap group were acquitted, however, of similar charges that followed a live performance in Hollywood, Fla.

After the obscenity declaration in Florida, officers here asked store operators to sign statements saying they had been given the warning. Risher refused.

Days after the warning, Patrick Weaver, whose mother is president of an anti-pornography group, bought the album at Risher's store and filed a complaint with police.

''I can't wait to get back to work,'' said Risher, owner of Hogwild Records and Tapes.

There was no immediate reaction from 2 Live Crew to Monday's dismissal.