TOLEDO, Ohio (AP) _ Police here are upset over a judge's ruling that they cannot prosecute a performer at an adult bookstore because she failed to arouse a vice officer who watched her act.

Officials of the Toledo vice/metro squad say they'll find another officer who is more excited by the show, and they vow a campaign against bookstore pornography will go on.

Judge Allen Andrews of Toledo Municipal court dismissed a charge of pandering obscenity against Melinda Safian, 30, of Toledo, after the arresting officer described Miss Safian's performance to the judge.

''The case was dismissed because I was not sexually aroused,'' Detective Ron Ziolkowski of the vice/metro squad said later.

The court ruled that the arousal factor was essential in proving that Safian's performance appealed to the officer's ''prurient interest,'' thereby meeting U.S. Supreme Court requirements for proving something obscene.

Capt. Derwish Mohamed, head of the special police squad, said he won't let the decision stop his campaign against vice.

''We are going to keep arresting them ... even if I have to find an officer whose prurient interest will be honestly offended, no matter how long that takes,'' Mohamed said.

Zilkowski said Miss Safian was arrested in October 1984 after he viewed her performance from a booth at the Modern Cinema on Toledo's west side.

''You go into the small booths, with telephones for private conversations with the performers, and put quarters, or tokens, into a small coin-operated machine which turns off the booth lights, allowing one to see the live performer on a stage on the other side of a plexiglass viewing window,'' he said.

''The more (money) I put in, the more risque the show got,'' he said.

But after hearing Zilkowski testify against Miss Safian in the trial that began Tuesday, defense attorney Sheldon Wittenberg filed for dismissal.

Andrews dismissed the case Wednesday. John Madigan, chief city prosecutor, said he did not know if his office will appeal the decision.