A quiet battle has taken shape in the courts here over the right of public library users to check out books without fear of state scrutiny of borrower records.

The issue involves two cases in which police officers have sought clues in library circulation files while investigating crimes. In one case they were successful. In the most recent case they have been thwarted, at least temporarily.

The Iowa Division of Criminal Investigation has recently been looking into a number of cattle mutilations in the state. It is believe the mutilations are the work of a religious cult. In each instance, blood has been drained from the animal. Its tongue tip and sex organs have been cut off and the intestines removed. DCI agents say the blood and organs are used in religious rituals.

In an effort to find leads the agents recently sought to obtain the circulation records of The Des Moines Public library, believing that those responsible for the mutilations may have consulted books on occult practices. They were refused, but returned with a court subpoena demanding the records.

The library board, asserting that the records were confidential, followed with a move to seek an injunction prohibiting the DCI from winning access to the records. A hearing has been set for later this month.

"We feel this is an extreme invasion of the right of people to read," said Elaine Estes, library director. "We feel people should be able to use the library without fear of being scrutinized by the state."

Furthermore, she said she didn't think the DCI really understood "what a complicated thing they were asking for."

"Our records are merely set up for the purpose of retrieving books, not for who checks out what," she said.

The Iowa Civil Liberties Union has also filed suit in the case, seeking an injunction both to prevent the library board from handing over the records and to prevent the DCI from obtaining them. That plea, too, is to be heard later this month.

The earlier case involved a murder investigation last April in Muscatine, in eastern Iowa. There the Muscatine County sheriff had sought and was given, records from a public library to learn if a suspect in the case had recently checked out certain books.

Initially, the library director, Dorothy Bemis, had refused the records. She was overruled by the library board, and the records were released to the sheriff.

The board's action was sharply criticized by the ICLU, which went to federal court in Des Moines seeking to close such records to the public. That suit too is to be heard later this month.

Complicating the effort to keep the library files private is a ruling by the Iowa attorney general that the records come under the provisions of the state's open records law. That opinion has prompted a move by the Iowa Citizen Privacy Task Force to seek a change in the law from the state legislature next year.